bluuebunny/crossref_metadata_2025 huggingface dataset:
Symmetrical and dissymmetrical 2,2′-bis-dipyrrin ligands and Zn(ii) binuclear helicates
Authors: Zhang Fan , Baudron Stéphane A. , Hosseini Mir Wais
Published: April 2018

A series of amide functionalized symmetrical and dissymmetrical 2,2′-bis-dipyrrin ligands has been prepared and characterized and their assembly with Zn(ii) towards the formation of binuclear helicates has been investigated.
A quinoline-based compound for explosive 2,4,6-trinitrophenol sensing: experimental and DFT-D3 studies
Authors: Halder Shibashis , Ghosh Pritam , Hazra Ananta , Banerjee Priyabrata , Roy Partha
Published: April 2018

A quinoline-based compound, 2,5-dimethylbis(quinolin-2-ylmethylene)benzene-1,4-diamine (DQB), has been found to be a turn-off chemosensor for 2,4,6-trinitrophenol.
A rhodamine-based fluorescent chemosensor for Al3+: is it possible to control the metal ion selectivity of a rhodamine-6G based chemosensor?
Authors: Roy Ankita , Mukherjee Rajat , Dam Bomba , Dam Somasri , Roy Partha
Published: April 2018

A rhodamine derivative 3′,6′-bis(ethylamino)-2-(2-(2-hydroxy-5-methylbenzylideneamino)ethyl)-2′,7′-dimethylspiro[isoindoline-1,9′-xanthen]-3-one has been found to be highly selective and sensitive chemosensor for Al3+ ion.
Update on Sporadic Colorectal Cancer Genetics
Authors: Hardiman Karin
Published: April 2018

Our understanding of the genetics of colorectal cancer has changed dramatically over recent years. Colorectal cancer can be classified in multiple different ways. Along with the advent of whole-exome sequencing, we have gained an understanding of the scale of the genetic changes found in sporadic colorectal cancer. We now know that there are multiple pathways that are commonly involved in the evolution of colorectal cancer including Wnt/β-catenin, RAS, EGFR, and PIK3 kinase. Another recent leap in our understanding of colorectal cancer genetics is the recognition that many, if not all tumors, are actually genetically heterogeneous within individual tumors and also between tumors. Recent research has revealed the prognostic and possibly therapeutic implications of various specific mutations, including specific mutations in BRAF and KRAS. There is increasing interest in the use of mutation testing for screening and surveillance through stool and circulating DNA testing. Recent advances in translational research in colorectal cancer genetics are dramatically changing our understanding of colorectal cancer and will likely change therapy and surveillance in the near future.
Colorectal Cancer in Inflammatory Bowel Disease
Authors: Higgins Peter , Stidham Ryan
Published: April 2018

Patients with inflammatory bowel disease (IBD) are at significantly increased risk of colorectal cancer (CRC), principally resulting from the pro-neoplastic effects of chronic intestinal inflammation. Epidemiologic studies continue to highlight the increased risk of CRC in IBD. However, the incidence has declined over the past 30 years, attributed to both successful CRC-surveillance programs and improved control of mucosal inflammation. Risk factors that further increase the risk of IBD-related CRC include disease duration, extent and severity, the presence of inflammatory pseudopolyps, coexistent primary sclerosing cholangitis, and a family history of CRC. All major professional societies agree that IBD-CRC surveillance should occur more frequently than in the general population. Yet, guidelines and consensus statements differ on the surveillance schedule and preferred method of surveillance. Improved sensitivity to previously “invisible” flat dysplastic lesions using high definition and chromoendoscopy methods has resulted in many guidelines abandoning requirements for random untargeted biopsies of the colon. While colonic dysplasia remains a worrisome finding, and several clinical scenarios remain best addressed by total proctocolectomy due to concerns of synchronous undetected lesions and the unpredictable tempo of progression to malignancy, better detection techniques have also increased opportunities for endoscopic resection of dysplastic lesions that can be clearly delineated. Finally, the expanding armamentarium of medical options in IBD, including anti-tumor necrosis factor and anti-adhesion biologic therapies, have substantially improved our ability to control severe inflammation and likely reduce the risk of CRC over time.
Emerging Systemic Therapies for Colorectal Cancer
Authors: Krauss John , Veenstra Christine
Published: April 2018

Despite advances over the past 20 years in colorectal cancer (CRC) screening, diagnosis, and treatment, survival outcomes remain suboptimal. Five-year survival for patients with locally advanced CRC is 69%; 5-year survival drops to 12% for patients with metastatic disease. Novel, effective systemic therapies are needed to improve long-term outcomes. In this review, we describe currently available systemic therapies for the treatment of locally advanced and metastatic CRC and discuss emerging therapies, including encouraging advances in identifying novel targeted agents and exciting responses to immunotherapeutic agents.
Development of Preclinical Models to Understand and Treat Colorectal Cancer
Authors: Sebolt-Leopold Judith
Published: April 2018

The establishment and validation of preclinical models that faithfully recapitulate the pathogenesis and treatment response of human colorectal cancer (CRC) is critical to expedient therapeutic advances in the clinical management of this disease. Integral to the application of precision medicine for patients diagnosed with metastatic CRC is the need to understand the molecular determinants of response for a given therapy. Preclinical models of CRC have proven invaluable in answering many of our basic questions relating to the molecular aberrations that drive colorectal tumor progression. This review will address the comparative merits and limitations of the broad spectrum of in vitro and in vivo models available for study of colorectal tumors and their response to experimental therapies.
Factors Affecting Postoperative Lung Expansion in Patients with Pyogenic Empyema
Authors: Ahn Hyo , Kim Yeong , I. Hoseok , Song Seunghwan , Eom Jung , Mok Jeongha , Cho Jeong
Published: April 2018

Background In patients with parapneumonic empyema, decortication is usually preferred to ensure functional lung re-expansion. However, there could be patients exhibiting incomplete postoperative lung expansion and inadequate drainage despite decortication. Therefore, we evaluated factors affecting postoperative lung expansion in patients undergoing decortication.

Methods A total of 221 patients with pyogenic empyema who underwent video-assisted thoracoscopic surgery (VATS) between January and October 2016 in our hospital were reviewed in terms of surgical success. The following factors were evaluated: age; the time between identification of a localized effusion and surgical referral; chest tube drainage durations; any underlying morbidity preoperative blood culture data; and the thickness of the visceral pleura.

Results Several factors that significantly prolonged the postoperative time to lung expansion were evident in patients with diabetes mellitus (DM) and bacteremia; postoperative chest tube drainage was significantly longer in those with DM (p = 0.009) and bacteremia (p = 0.01); and postoperative hospitalization time was significantly longer in patients with bacteremia (p = 0.01). The thickness of the visceral pleura was strongly correlated with postoperative chest tube drainage duration and postoperative hospitalization time (Pearson correlation coefficient, r = 0.245, p = 0.00).

Conclusions In patients with DM, bacteremia, or thickened pleura, the time to lung expansion after operation was longer. Therefore, stricter pre- and post-operative control of blood-sugar levels and adequate antibiotics are required to facilitate postoperative lung re-expansion. In patients with thickened pleurae, prolonged chest tube placement is unavoidable.
Heparin-Induced Thrombocytopenia in Infants after Heart Surgery
Authors: Abdillah Juma , Hu Qinghua , Chen Xuliang , Chen Xing , Zhou Wu , Luo Wanjun , Huang Lingjin
Published: April 2018

Background Heparin-induced thrombocytopenia (HIT) in infants is a rare disorder, and the diagnosis and management of HIT still remains challenging. Argatroban is a synthetic direct thrombin inhibitor (DTI) that is widely used for treating HIT. However, little is known about the efficacy of the activated clotting time (ACT) test in monitoring DTI treatment as an alternative to the routinely used activated partial thromboplastin time (aPTT).

Methods Between July 2013 and January 2015, four infants were diagnosed with HIT after surgical correction of congenital anomalies. In all cases, heparin was used during cardiopulmonary bypass (CPB). Diagnosis of HIT was based on the “4 Ts” pretest clinical scoring system, and platelet factor 4 (PF4) antibody was detected using enzyme-linked immunosorbent assay. Argatroban was used in treating HIT. When argatroban was infused, anticoagulation tests (aPTT, prothrombin time [PT], thrombin time [TT], and fibrinogen) were performed every 4 to 12 hours. ACT was used in addition to monitor the anticoagulation effect of argatroban. The target ACT was 1.5 to 3.0 times the baseline. ACT was measured every 2 to 4 hours and remeasured 1 hour after each dosage adjustment.

Results Thrombocytopenia (defined as a 50% decrease in platelet count) occurred during the 3rd to 6th day postoperatively. After the diagnosis of HIT, argatroban was started immediately, and platelet counts stabilized and gradually increased. Anticoagulation effect of argatroban was successful monitored by ACT and aPTT. Poor correlation between the ACT test and aPTT test (R = 0.270, p = 0.092) was noted in one patient. ACT values increased rapidly after 3 to 7 days on argatroban treatment. In most cases, low dosage of argatroban was given ranging from 0.04 to 5.00 μg/kg/min.

Conclusion Argatroban may be an effective medicine in treating HIT in infants, in a reduced dosage. The great fluctuation in argatroban dosage during the course of HIT treatment necessitates close monitoring. ACT test may be reliable and convenient for monitoring HIT treatment and may contribute to positive clinical outcomes in infants. The efficacy of argatroban and the use of ACT monitoring in the management of HIT infants needs further study.
Alternative Choices for Anterolateral Thigh Flaps Lacking Suitable Perforators: A Systematic Review
Authors: Namgoong Sik , Yoon Young , Yoo Ki , Han Seung , Kim Woo , Dhong Eun
Published: April 2018

Background The anterolateral thigh (ALT) flap has become a predominant option in the field of reconstruction. However, some difficulties in harvesting flap exist due to the anatomical variability of the perforators. Reports have provided solutions for unreliable perforators. Although numerous cases that showed successful conversion to tensor fasciae latae (TFL) flap or anteromedial thigh (AMT) flap have been reported in the literature, none fully addresses the reliability of the perforators that have been described to date. Therefore, we conducted a systematic literature review to compare the reliability of the TFL flap with that of the AMT flap when an ALT flap perforator is not suitable.

Methods A systematic review of the MEDLINE, PubMed, and Cochrane Library electronic databases was performed to compare the characteristics of TFL and AMT flap perforators.

Results A total of 13 articles were included for review. The mean number of TFL perforators varied from 1.41 to 3.17 per thigh. The mean number of AMT perforators was between 0.59 and 1.3 per thigh. The cumulative assessment of the clinical and anatomical studies showed 456 perforators in 180 TFL flaps (mean, 2.53) and 145 perforators in 162 AMT flaps (mean, 0.90). The mean pedicle length of the TFL and AMT flaps ranged from 7.0 to 9.59 cm and from 7.4 to 11.0 cm, respectively. The mean perforator diameter was similar in both flaps.

Conclusion Currently available literature suggests that the TFL flap may be a more reliable alternative when adequate perforators are not found for ALT flap harvest.
Does Cigarette Smoking Harm Microsurgical Free Flap Reconstruction?
Authors: Heidekrueger Paul , Haas Elisabeth , Coenen Michaela , Giunta Riccardo , Ninkovic Milomir , Broer P. , Ehrl Denis
Published: April 2018

Background Free tissue transfers can successfully address a wide range of reconstructive requirements. While the negative influence of cigarette smoking is well documented, its effects in the setting of microsurgical free flap reconstruction remain debated. This study evaluates the impact of cigarette smoking on microsurgical reconstructions.

Methods Over a 7-year period, 897 patients underwent 969 microvascular free flap reconstructions at a single surgical center. The cases were divided into “smoker” (S) and “nonsmoker” (NS) groups according to their cigarette smoking status. The data were retrospectively screened for patients' demographics, perioperative details, surgical complications, free flap types, recipient sites, flap survival, and overall outcomes.

Results Both groups were comparable regarding comorbidities including hypertension, peripheral artery disease, diabetes, American Society of Anesthesiologists scores, types of performed free flaps, and recipient sites. While patients in the NS group were significantly older and had a higher prevalence of obesity (p < 0.05), there were no significant differences regarding the rate of major or minor complications during our 3-month follow-up period (p > 0.05).

Conclusion While minor and major complications were increased regarding virtually all examined parameters, cigarette smoking did not have significant effects on the overall outcomes of microsurgical free flap reconstructions.
Check the Record: Remote CT Scans for Breast Flap Perforator Mapping
Authors: Sergesketter Amanda , Pyfer Bryan , Phillips Brett , Zhao Ruya , Hollenbeck Scott
Published: April 2018

Background Perforator mapping with computed tomography angiography (CTA) prior to autologous breast reconstruction reduces donor-site morbidity and operative time, but is costly. The aim of this study was to evaluate whether pre-existing CT scans could be used for dominant perforator identification before autologous reconstruction.

Methods We identified all female patients who underwent mastectomy with immediate or delayed breast reconstruction with abdominal free flaps at a single institution between 2006 and 2016. Medical records were reviewed to identify patients with pre-existing CT scans of the abdomen/pelvis. CT images were reviewed by the senior surgeon and ranked on a 1 to 3 scale to indicate utility for preoperative planning. An analysis was performed to assess financial savings and radiation avoidance associated with the use of pre-existing scans.

Results Of 301 identified patients, 44.9% (n = 135) had an available pre-existing CT. A dominant perforator was identified on 92.6% of scans. A higher proportion of dominant perforators was identified using positron emission tomography (PET)/CT scans compared with CT scans with intravenous (IV) contrast and noncontrast CTs (p < 0.0001). Compared with PET/CTs and CTs with IV contrast, the average utility score for noncontrast CTs was lower (p = 0.0001). Dominant perforators were clearly identified in patients who had both a remote CT scan and a preoperative CTA. Perforator mapping using remote CT scans yielded a projected radiation reduction of 13.2 mGy per patient and yielded a projected annual U.S. health care savings of $28,459,638.

Conclusion Our study suggests that pre-existing CT scans represent a viable and economical alternative for perforator mapping before abdominal-based free flap breast reconstruction.
Female Sexual Function in Women with Suspected Deep Infiltrating Endometriosis
Authors: Lima Ryane Vieira , Pereira Ana Maria Gomes , Beraldo Fernando Bray , Gazzo Cláudia , Martins João Alfredo , Lopes Reginaldo Guedes Coelho
Published: April 2018

Objective To evaluate the quality of the sexual function of women with suspected deep infiltrating endometriosis.

Methods A cross-sectional, observational and prospective study was conducted between May 2015 and August 2016, in which 67 patients with deep infiltrating endometriosis, suspected or diagnosed, were assessed for epidemiological and clinical characteristics, such as pain level through a visual analog scale (VAS), features of deep infiltrating endometriosis lesions and score on the Female Sexual Function Index (FSFI) before the onset of treatment. The statistical analysis was performed using the software STATA version 12.0 (StataCorp LLC, College Station, TX, USA) to compare the variables through multiple regression analysis.

Results The average age of the patients was 39.2 years old; most patients were symptomatic (92.5%); and the predominant location of the deep infiltrating lesions was on the rectosigmoid colon (50%), closely followed by the retrocervical region (48.3%). The median overall score on the FSFI was 23.4; in 67.2% of the cases the score was ≤ 26.5 (cutoff point for sexual dysfunction). Deep dyspareunia (p = 0.000, confidence interval [CI]: 0.64–0.83) and rectosigmoid endometriosis lesions (p = 0.008, CI: 0.72–0.95) showed significant correlation with lower FSFI scores, adjusted by bladder lesion, patients' age and size of lesions. Deep dyspareunia (p = 0.003, CI: 0.49–0.86) also exhibited significant correlation with FSFI pain domain, adjusted by cyclic bowel pain, vaginal lesion and use of gonadotropin-releasing hormone (GnRH) analog. These results reflect the influence of deep dyspareunia on the sexual dysfunction of the analyzed population.

Conclusion Most patients exhibited sexual dysfunction, and deep dyspareunia was the pelvic painful symptom that showed correlation with sexual dysfunction.
Development of Targeted Muscle Reinnervation Model in Hind Limb Amputated Rats
Authors: Garg Rohit , Uygur Safak , Cwykiel Joanna , Siemionow Maria
Published: April 2018

Background Targeted muscle reinnervation (TMR) is a novel approach to postamputation neuroma pain; however, this has not been explicitly studied. The purpose of this study was to develop a TMR model in hind limb amputated rats.

Methods Ten hind limbs from 5 Sprague Dawley cadaver rats were used. Sciatic nerve, main branches of the sciatic nerve (common peroneal, tibial, sural), motor branches from the sciatic nerve to the biceps femoris and cauda femoris, gluteal nerve and its motor branches to the semimembranosus, and biceps femoris and femoral nerve were dissected to look for consistent nerve anatomy that can be used for TMR in the rat hind limb amputation model. Transfemoral amputation was performed and two types of coaptations were made: common peroneal nerve to motor branch to biceps femoris and tibial nerve to motor branch to semimembranosus.

Results The total surgical time for the dissection, amputation, and coaptation of nerves was ∼90 minutes. A total of 100 nerves were dissected in 10 rat hind limbs. Anatomical dissections were straightforward to perform. Anatomy of the dissected nerves was consistent. Hind limb amputations were performed without damaging the target muscles and nerves. Nerve lengths were sufficient for coaptation without any tension.

Conclusions To the best of our knowledge, this is the first report on TMR model in hind limb amputated rats. This model will allow for mechanical, electromyography (EMG), and histological analysis for future assessment of neuroma prevention.
Update Pharmakotherapie bei Parkinson
Authors: Ceballos-Baumann A. O. , Fietzek U. M.
Published: April 2018

Auch im letzten Jahr wurden zahlreiche pharmakotherapeutische Entwicklungen für die Parkinsonkrankheit vorangebracht. Die in den USA kommerziell erfolgreiche retardierte Darreichungsform von Levodopa IPX066 ist in Europa zwar zugelassen, aber nicht am Markt verfügbar. Eine speziell gefaltete Akkordeon Pille verspricht ebenso eine vereinfachte Galenik bei besserer klinischer Wirkung. Levodopa ist als Inhalativum kurz vor Markteintritt und zeigt in den vorgelegten Studien, dass Off-Phasen erfolgreich verkürzt werden können, allerdings nicht schnellere Hilfe leisten als die verfügbaren Stand-by Medikamente. Neu ist auch, dass L-Dopa über die Haut appliziert werden kann. Safinamid und Opicapon sind über Rezept verfügbar. Für letzteres liegen die Ergebnisse der Zulassungsstudien vor. Die neue AmantadinGalenik hat in den USA aufgrund günstiger Studiendaten die Zulassung zur Behandlung von Dyskinesien erhalten. Auch hat sich das Verständnis um Risikofaktoren zur Entwicklung eines Parkinson deutlich weiterentwickelt. Wir stellen neueste Arbeiten zu dem Glucagon-like-Peptid-Analogon Exenatide und dem ß2-Adrenorezeptor vor.
Genetisch determinierte Dystonien
Authors: Lohmann K. , Paus S. , Lohmann E. , Gasser T. , Ganos C. , Klein C. , Brüggemann N.
Published: April 2018

Dystonien sind durch anhaltende oder intermittierende Muskelkontraktionen gekennzeichnet, die zu abnormen, häufig repetitiven Bewegungen verschiedener Körperteile führen. Die Einteilung der Dystonien erfolgt nach klinischen und ätiologischen Kriterien, wobei insbesondere die Genetik durch die Identifikation neuer, mit der Krankheit assoziierter Gene an Bedeutung gewonnen hat.

Innerhalb des Krankheitsbildes der Dystonie können folgende Formen voneinander unterschieden werden: bei den isolierten Formen bestehen keine über die Dystonie hinausgehenden Zeichen oder Symptome; kombinierte Dystonien zeichnen sich durch eine Kombination von Dystonie und anderen Bewegungsstörungen wie Parkinsonismus, Chorea und Myoklonien aus und bei den komplexen Dystonien finden sich weitere neurologische und nicht-neurologische Manifestationen. Mutationen in den folgenden Genen sind mittlerweile als etablierte Ursachen für isolierte oder kombinierte erbliche Dystonie identifiziert worden: Tor1A, THAP1, GNAL, ANO3, KMT2B, GCH1, TAF1, PRKRA, ATP1A3, SGCE und ADCY5; > 100 Gene stehen im Zusammenhang mit komplexen Dystonien. Viele, insbesondere auch einige genetisch bedingte Formen der Dystonien, sprechen auf die Therapieoption der tiefen Hirnstimulation gut an. Aktuell arbeiten Forschungsnetzwerke daran, die Diagnostik und Therapie der Dystonien weiter zu verbessern.
Committor of elementary reactions on multistate systems
Authors: Király Péter , Kiss Dóra Judit , Tóth Gergely
Published: April 2018

In our study, we extend the committor concept on multi-minima systems, where more than one reaction may proceed, but the feasible data evaluation needs the projection onto partial reactions. The elementary reaction committor and the corresponding probability density of the reactive trajectories are defined and calculated on a three-hole two-dimensional model system explored by single-particle Langevin dynamics. We propose a method to visualize more elementary reaction committor functions or probability densities of reactive trajectories on a single plot that helps to identify the most important reaction channels and the nonreactive domains simultaneously. We suggest a weighting for the energy-committor plots that correctly shows the limits of both the minimal energy path and the average energy concepts. The methods also performed well on the analysis of molecular dynamics trajectories of 2-chlorobutane, where an elementary reaction committor, the probability densities, the potential energy/committor, and the free-energy/committor curves are presented.
In situ/non-contact superfluid density measurement apparatus
Authors: Nam Hyoungdo , Su Ping-Hsang , Shih Chih-Kang
Published: April 2018

We present a double-coil apparatus designed to operate with in situ capability, which is strongly desired for superconductivity studies on recently discovered two-dimensional superconductors. Coupled with a scanning tunneling microscope, the study of both local and global superconductivity [for superconducting gap and superfluid density (SFD), respectively] is possible on an identical sample without sample degradations due to damage, contamination, or oxidation in an atmosphere. The performance of the double-coil apparatus was tested on atomically clean surfaces of non-superconducting Si(111)-7 × 7 and on superconducting films of 100 nm-thick Pb and 1.4 nm-ultrathin Pb. The results clearly show the normal-to-superconductor phase transition for Pb films with a strong SFD.
Evolution of electrical properties and domain configuration of Mn modified Pb(In1/2Nb1/2)O3-PbTiO3 single crystals
Authors: Qiao Huimin , He Chao , Yuan Feifei , Wang Zujian , Li Xiuzhi , Liu Ying , Guo Haiyan , Long Xifa
Published: April 2018

The acceptor doped relaxor-based ferroelectric materials are useful for high power applications such as probes in ultrasound-guided high intensity focused ultrasound therapy. In addition, a high Curie temperature is desired because of wider temperature usage and improved temperature stability. Previous investigations have focused on Pb(Mg1/3Nb2/3)O3-PbTiO3 and Pb(Zn1/3Nb2/3)O3-PbTiO3 systems, which have a ultrahigh piezoelectric coefficient and dielectric constant, but a relatively low Curie temperature. It is desirable to study the binary relaxor-based system with a high Curie temperature. Therefore, Pb(In1/2Nb1/2)O3-PbTiO3 (PINT) single crystals were chosen to study the Mn-doped influence on their electrical properties and domain configuration. The evolution of ferroelectric hysteresis loops for doped and virgin samples exhibit the pinning effect in Mn-doped PINT crystals. The relaxation behaviors of doped and virgin samples are studied by fit of the modified Curie-Weiss law and Volgel-Fucher relation. In addition, a short-range correlation length was fitted to study the behavior of polar nanoregions based on the domain configuration obtained by piezoresponse force microscopy. Complex domain structures and smaller short-range correlation lengths (100–150 nm for Mn-doped PINT and >400 nm for pure PINT) were obtained in the Mn-doped PINT single crystals.
An integrated single- and two-photon non-diffracting light-sheet microscope
Authors: Lau Sze Cheung , Chiu Hoi Chun , Zhao Luwei , Zhao Teng , Loy M. M. T. , Du Shengwang
Published: April 2018

We describe a fluorescence optical microscope with both single-photon and two-photon non-diffracting light-sheet excitations for large volume imaging. With a special design to accommodate two different wavelength ranges (visible: 400-700 nm and near infrared: 800-1200 nm), we combine the line-Bessel sheet (LBS, for single-photon excitation) and the scanning Bessel beam (SBB, for two-photon excitation) light sheet together in a single microscope setup. For a transparent thin sample where the scattering can be ignored, the LBS single-photon excitation is the optimal imaging solution. When the light scattering becomes significant for a deep-cell or deep-tissue imaging, we use SBB light-sheet two-photon excitation with a longer wavelength. We achieved nearly identical lateral/axial resolution of about 350/270 nm for both imagings. This integrated light-sheet microscope may have a wide application for live-cell and live-tissue three-dimensional high-speed imaging.
2D lateral heterostructures of group-III monochalcogenide: Potential photovoltaic applications
Authors: Cheng Kai , Guo Yu , Han Nannan , Jiang Xue , Zhang Junfeng , Ahuja Rajeev , Su Yan , Zhao Jijun
Published: April 2018

Solar photovoltaics provides a practical and sustainable solution to the increasing global energy demand. Using first-principles calculations, we investigate the energetics and electronic properties of two-dimensional lateral heterostructures by group-III monochalcogenides and explore their potential applications in photovoltaics. The band structures and formation energies from supercell calculations demonstrate that these heterostructures retain semiconducting behavior and might be synthesized in laboratory using the chemical vapor deposition technique. According to the computed band offsets, most of the heterojunctions belong to type II band alignment, which can prevent the recombination of electron-hole pairs. Besides, the electronic properties of these lateral heterostructures can be effectively tailored by the number of layers, leading to a high theoretical power conversion efficiency over 20%.
SrFe12O19 based ceramics with ultra-low dielectric loss in the millimetre-wave band
Authors: Yu Chuying , Zeng Yang , Yang Bin , Wylde Richard , Donnan Robert , Wu Jiyue , Xu Jie , Gao Feng , Abrahams Isaac , Reece Mike , Yan Haixue
Published: April 2018

Non-reciprocal devices such as isolators and circulators, based mainly on ferromagnetic materials, require extremely low dielectric loss in order for strict power-link budgets to be met for millimetre (mm)-wave and terahertz (THz) systems. The dielectric loss of commercial SrFe12O19 hexaferrite was significantly reduced to below 0.002 in the 75–170 GHz band by thermal annealing. While the overall concentration of Fe2+ and oxygen vacancy defects is relatively low in the solid, their concentration at the surface is significantly higher, allowing for a surface sensitive technique such as XPS to monitor the Fe3+/Fe2+ redox reaction. Oxidation of Fe2+ and a decrease in oxygen vacancies are found at the surface on annealing, which are reflected in the bulk sample by a small change in the unit cell volume. The significant decrease in the dielectric loss property can be attributed to the decreased concentration of charged defects such as Fe2+ and oxygen vacancies through the annealing process, which demonstrated that thermal annealing could be effective in improving the dielectric performance of ferromagnetic materials for various applications.
Investigation of unsteady, hypersonic, laminar separated flows over a double cone geometry using a kinetic approach
Authors: Tumuklu Ozgur , Levin Deborah A. , Theofilis Vassilis
Published: April 2018

Shock-dominated hypersonic laminar flows over a double cone are investigated using time accurate direct simulation Monte Carlo combined with the residuals algorithm for unit Reynolds numbers gradually increasing from 9.35 × 104 to 3.74 × 105 m−1 at a Mach number of about 16. The main flow features, such as the strong bow-shock, location of the separation shock, the triple point, and the entire laminar separated region, show a time-dependent behavior. Although the separation shock angle is found to be similar for all Re numbers, the effects of Reynolds number on the structure and extent of the separation region are profound. As the Reynolds number is increased, larger pressure values in the under-expanded jet region due to strong shock interactions form more prominent λ-shocklets in the supersonic region between two contact surfaces. Likewise, the surface parameters, especially on the second cone surface, show a strong dependence on the Reynolds number, with skin friction, pressure, and surface heating rates increasing and velocity slip and temperature jump values decreasing for increasing Re number. A Kelvin-Helmholtz instability arising at the shear layer results in an unsteady flow for the highest Reynolds number. These findings suggest that consideration of experimental measurement times is important when it comes to determining the steady state surface parameters even for a relatively simple double cone geometry at moderately large Reynolds numbers.
Expanding the calculation of activation volumes: Self-diffusion in liquid water
Authors: Piskulich Zeke A. , Mesele Oluwaseun O. , Thompson Ward H.
Published: April 2018

A general method for calculating the dependence of dynamical time scales on macroscopic thermodynamic variables from a single set of simulations is presented. The approach is applied to the pressure dependence of the self-diffusion coefficient of liquid water as a particularly useful illustration. It is shown how the activation volume associated with diffusion can be obtained directly from simulations at a single pressure, avoiding approximations that are typically invoked.
Frequency pulling in a low-voltage medium-power gyrotron
Authors: Luo Li , Du Chao-Hai , Huang Ming-Guang , Liu Pu-Kun
Published: April 2018

Many recent biomedical applications use medium-power frequency-tunable terahertz (THz) sources, such as sensitivity-enhanced nuclear magnetic resonance, THz imaging, and biomedical treatment. As a promising candidate, a low-voltage gyrotron can generate watt-level, continuous THz-wave radiation. In particular, the frequency-pulling effect in a gyrotron, namely, the effect of the electron beam parameters on the oscillation frequency, can be used to tune the operating frequency. Most previous investigations used complicated and time-consuming gyrotron nonlinear theory to study the influence of many beam parameters on the interaction performance. While gyrotron linear theory investigation demonstrates the advantages of rapidly and clearly revealing the physical influence of individual key beam parameters on the overall system performance, this paper demonstrates systematically the use of gyrotron linear theory to study the frequency-pulling effect in a low-voltage gyrotron with either a Gaussian or a sinusoidal axial-field profile. Furthermore, simulations of a gyrotron operating in the first axial mode are carried out in the framework of nonlinear theory as a contrast. Close agreement is achieved between the two theories. Besides, some interesting results are obtained. In a low-current sinusoidal-profile cavity, the ranges of frequency variation for different axial modes are isolated from each other, and the frequency tuning bandwidth for each axial mode increases by increasing either the beam voltage or pitch factor. Lowering the voltage, the total tuning ranges are squeezed and become concentrated. However, the isolated frequency regions of each axial mode cannot be linked up unless the beam current is increased, meaning that higher current operation is the key to achieving a wider and continuous tuning frequency range. The results presented in this paper can provide a reference for designing a broadband low-voltage gyrotron.
Metrological 2iOF fibre-optic system for position and displacement measurement with 31 pm resolution
Authors: Orłowska Karolina , Świątkowski Michał , Kunicki Piotr , Gotszalk Teodor
Published: April 2018

In the present paper, we describe a high sensitivity intensity fibre-optic displacement sensor with tens of picometre resolution combined with a sub-picometre resolution interferometric calibration system. Both integrated components form the so-called “2 in one ferrule” system 2iOF. The design and construction of the presented device depend on integrating two sensors’ systems within one fibre-optic measuring head, which allows performing in situ calibration process with no additional time-consuming adjustment procedure. The resolution of the 2iOF system is 31 pm/Hz1/2 obtained with an interferometric Fabry-Perot based calibration system—providing accuracy better than tens of fm/Hz1/2 within 1 MHz bandwidth in the measurement range of up to 100 μm. The direct response from the intensity sensor is then the 2iOF output one. It is faster and more convenient to analyze in comparison, with much better resolution (3 orders of magnitude higher) but on the other hand also more time consuming and dependent on the absolute sample position interferometer. The proposed system is flexible and open to various applications. We will present the results of the piezoelectrical actuator displacement measurements, which were performed using the developed system.
Silicon-based quantum dots have a path to scalable quantum computing
Authors: Wilson R. Mark
Published: April 2018

Two research groups demonstrate the coherent interaction between the spin of a single electron and a single microwave photon.
Displaced scientists strive to restart professional lives in new lands
Authors: Feder Toni
Published: April 2018

Record numbers of scientists are fleeing persecution and conflict. Host universities and communities can benefit from the brain gain.
Physicists decry cuts to inertial fusion program
Authors: Kramer David
Published: April 2018

Basic research in astrophysics and other fields also would be set back by the reprioritizing of the Department of Energy’s weapons program.
Superlubricity: Friction’s vanishing act
Authors: Martin Jean Michel , Erdemir Ali
Published: April 2018

By carefully orchestrating atomic-scale interactions, one can coax hard surfaces to slide against one another with virtually no resistance.
Lubrication of articular cartilage
Authors: Jahn Sabrina , Klein Jacob
Published: April 2018

A mix of proteins, polymers, lipids, and tightly bound but fluid shells of water molecules may account for a healthy joint’s ultralow friction.
Imaging black holes
Authors: Psaltis Dimitrios , Özel Feryal
Published: April 2018

The Event Horizon Telescope will combine data from a worldwide network of radio telescopes to image the shadow that a black hole casts on the surrounding plasma.
Autochthonous tumors driven by
Rb1
loss have an ongoing requirement for the RBP2 histone demethylase
Authors: McBrayer Samuel K. , Olenchock Benjamin A. , DiNatale Gabriel J. , Shi Diana D. , Khanal Januka , Jennings Rebecca B. , Novak Jesse S. , Oser Matthew G. , Robbins Alissa K. , Modiste Rebecca , Bonal Dennis , Moslehi Javid , Bronson Roderick T. , Neuberg Donna , Nguyen Quang-De , Signoretti Sabina , Losman Julie-Aurore , Kaelin William G.
Published: April 2018

Significance

Developing therapeutic strategies for tumors driven by tumor suppressor gene inactivation, as opposed to oncogene activation, represents a significant challenge in oncology. While restoration of tumor suppressor functionality is generally not feasible, inhibiting proteins that act downstream of lost tumor suppressors represents one strategy to overcome this challenge. In this study, we applied this concept to the tumor suppressor gene
retinoblastoma 1
(
RB1
). The
RB1
gene product, pRB, associates with the RBP2 histone demethylase and RBP2 is deregulated in
RB1
-null cancers. Here, we show that genetic ablation of RBP2 in established, autochthonous pRB-defective murine tumors retards their growth and enhances mouse survival. Our findings provide a further rationale for the development and testing of pharmacological RBP2 inhibitors for cancer treatment.
Ectopic neurogenesis induced by prenatal antiepileptic drug exposure augments seizure susceptibility in adult mice
Authors: Sakai Atsuhiko , Matsuda Taito , Doi Hiroyoshi , Nagaishi Yukiko , Kato Kiyoko , Nakashima Kinichi
Published: April 2018

Significance

Recent clinical studies suggest that environmental insults, such as valproic acid (VPA) exposure, in utero can have adverse effects on brain function of the offspring in later life, although the underlying mechanisms of these impairments remain poorly understood. By focusing on the property of neural stem/progenitor cells (NS/PCs) residing in the adult hippocampus, we identified the mechanism of increased seizure sensitivity in prenatally VPA-exposed adult mice. Furthermore, we found that voluntary exercise can overcome the adverse effects through normalizing VPA-induced transcriptome alterations in NS/PCs. We believe that our study provides insights for further understanding and developing treatment strategies for neurological disorders induced by prenatal environmental insults.
Thermodynamic limits of energy harvesting from outgoing thermal radiation
Authors: Buddhiraju Siddharth , Santhanam Parthiban , Fan Shanhui
Published: April 2018

Significance

A large part of the research on renewable energy has focused on harvesting power from solar radiation. But, for the Earth to maintain its temperature, it must radiate to the outer space an amount of power approximately equal to that of the incoming solar radiation. However, far less is understood about the theoretical limits of harvesting power from such outgoing radiation. Here, we identify a duality relation between harvesting incoming and outgoing thermal radiation and use it to derive fundamental limits of harvesting outgoing thermal radiation. Our results indicate a theoretical limit that far exceeds what was previously thought to be possible and highlight the significant potential for harvesting outgoing thermal radiation for renewable energy applications.
Long-term in vivo recording of circadian rhythms in brains of freely moving mice
Authors: Mei Long , Fan Yanyan , Lv Xiaohua , Welsh David K. , Zhan Cheng , Zhang Eric Erquan
Published: April 2018

Significance

In mammals, the suprachiasmatic nucleus (SCN) synchronizes circadian rhythms in cells throughout the body to the environmental light/dark cycle. We have developed a fluorescence-based technology that enables long-term monitoring of clock gene expression in particular brain nuclei and specific types of neurons at high temporal resolution, in freely moving mice, in a light/dark cycle. Using this system, we demonstrate the dynamics of
Per2
and
Cry1
transcriptional rhythms in SCN vasoactive intestinal peptide (VIP) neurons following an 8-h phase advance in the light/dark cycle.
Human bony labyrinth is an indicator of population history and dispersal from Africa
Authors: Ponce de León Marcia S. , Koesbardiati Toetik , Weissmann John David , Milella Marco , Reyna-Blanco Carlos S. , Suwa Gen , Kondo Osamu , Malaspinas Anna-Sapfo , White Tim D. , Zollikofer Christoph P. E.
Published: April 2018

Significance

The cavity system of the inner ear—the so-called bony labyrinth—houses the senses of balance and hearing. This structure is embedded in dense petrous bone, fully formed by birth and generally well preserved in human skeletal remains, thus providing a rich source of morphological information about past populations. Here we show that labyrinthine morphology tracks genetic distances and geography in an isolation-by-distance model with dispersal from Africa. Because petrous bones have become prime targets of ancient DNA recovery, we propose that all destructive studies first acquire high-resolution 3D computed-tomography data prior to any invasive sampling. Such data will constitute an important archive of morphological variation in past and present populations, and will permit individual-based genotype–phenotype comparisons.
Transcriptional mutagenesis mediated by 8-oxoG induces translational errors in mammalian cells
Authors: Dai Da-Peng , Gan Wei , Hayakawa Hiroshi , Zhu Jia-Lou , Zhang Xiu-Qing , Hu Guo-Xin , Xu Tao , Jiang Zhe-Li , Zhang Li-Qun , Hu Xue-Da , Nie Ben , Zhou Yue , Li Jin , Zhou Xiao-Yang , Li Jian , Zhang Tie-Mei , He Qing , Liu Dong-Ge , Chen Hai-Bo , Yang Nan , Zuo Ping-Ping , Zhang Zhi-Xin , Yang Huan-Ming , Wang Yao , Wilson Samuel H. , Zeng Yi-Xin , Wang Jian-Ye , Sekiguchi Mutsuo , Cai Jian-Ping
Published: April 2018

Significance

We had previously shown that 8-oxoG:A mismatch pairing can occur at both the DNA and RNA levels, thus causing base substitutions in DNA and translation errors, respectively. However, little attention has been paid to the biological significance of oxidized mRNA or to the clearance mechanism for such RNA lesions in mammalian cells. Here, we developed a sensitive reporter system to capture sequence-altered proteins that are translated from 8-oxoG–containing mRNAs. Also, we applied a deep-sequencing method to measure the content of these sequence-changed mRNAs to correlate the relationship between 8-oxoG–containing mRNAs and sequence-altered proteins. Additionally, we found that the accumulation of 8-oxoG in RNA can accelerate the production of pathogenic amyloid β peptides in mammalian cells.
Spatial organization and dynamics of RNase E and ribosomes inCaulobacter crescentus
Authors: Bayas Camille A. , Wang Jiarui , Lee Marissa K. , Schrader Jared M. , Shapiro Lucy , Moerner W. E.
Published: April 2018

Significance

Regulated gene expression involves accurate subcellular positioning and timing of RNA synthesis, degradation, processing, and translation. RNase E is an endoribonuclease that forms the scaffold of the RNA degradosome in bacteria, responsible for the majority of mRNA turnover and RNA processing. We used 3D superresolution microscopy and single-particle tracking to quantify the spatial distribution and dynamics of RNase E and ribosomes in the asymmetrically dividing bacteriumCaulobacter crescentus. Our results show that active transcription and RNA substrate availability facilitate confinement and clustering of both RNase E and ribosomes. RNase E clusters colocalized with the subcellular position of the twoCaulobacterrRNA gene chromosomal loci, indicating that RNA processing can be spatially organized in a bacterium according to its transcriptional profile.
A small-molecule fragment that emulates binding of receptor and broadly neutralizing antibodies to influenza A hemagglutinin
Authors: Kadam Rameshwar U. , Wilson Ian A.
Published: April 2018

Significance

Influenza is a contagious and sometimes lethal disease of the human respiratory tract. Current preventative measures include annual vaccination and a limited number of antiviral drugs. However, the effectiveness of the seasonal vaccine is unpredictable, and resistance has been developing to all approved drugs. Therefore, novel influenza therapeutics with new targets and mechanisms are essential to protect against future pandemics, epidemics, and seasonal flu. Here, we report on the serendipitous discovery of a noncarbohydrate-based small-molecule
N
-cyclohexyltaurine that binds to the receptor-binding site of influenza virus hemagglutinin. Our structural findings provide much needed insights on how to effectively and specifically target the hemagglutinin receptor-binding site with small-molecule ligands, a goal which has evaded researchers for many years.
The Reception of Ezra Pound and T. S. Eliot in Prewar Japan
Authors: Nagahata Akitoshi
Published: April 2018

Modernist literature was introduced to Japan in the early 20th century, and some of it took root. While modernism, a new movement in art and literature, was first developed in Europe, American poets, especially Ezra Pound and T. S. Eliot, played a major role in its development. Both of these poets were expatriates, living in Europe after they left the United States. As this fact indicates, there was an international, cosmopolitan nature to modernism, which was also seen in other modernist writers and poets, such as James Joyce, Gertrude Stein, Hilda “H. D.” Doolittle, Mina Loy, Djuna Barnes, and Eugene Jolas, to name just a few; this internationalist appeal was also an important factor in the early reception of modernism by the Japanese. In literature in English, Noguchi Yonejirō (Yone Noguchi) and Nishiwaki Junzaburō, for example, had contact with modernist writers abroad, published their own works in English, and introduced foreign poets they knew to Japanese readers. Takahashi Shinkichi, Kitasono Katue (Kitazono Katsue), and other poets also had correspondence with poets and writers of foreign countries and exchanged their works.

Following the initial encounter between Japanese poets and modernist American poets at the beginning of the 20th century, their works were introduced to Japanese readers of literature in English in the late 1920s. At the time, within academia, American literature was still considered part of English literature. Although mass-market literature series included many American literature titles, especially novels, the curricula in the English departments at major universities rarely included American literature. Besides, even in English literature studies, the focus was mainly on 19th-century (and earlier) authors, and modernist poetry was still not getting much attention. Thus, the reception of modernist American poetry in Japanese academia was generally slow. Instead, it was literary magazines such as Shi to shiron that actively introduced modernist poetry (including Gertrude Stein, T. S. Eliot, and Ezra Pound) to Japanese readers. Modernist poetry in English was often seen as “intellectualist” in Japan. As the control of freedom of speech and publication tightened in the late 1930s and the 1940s, in keeping with Japan’s militarization and totalitarianism, it became difficult to read and write about foreign literature. In this situation, adhering to modernist and intellectualist literature assumed its symbolic meaning of resistance. While under totalitarian rule, older Japanese modernists converted themselves into collaborationists, and younger poets such as Ayukawa Nobuo, who started a magazine called Arechi (The waste land), tried their best to maintain their literary independence. They became leading figures in postwar Japanese poetry.