bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamics and Oxidation Behaviour of Crystalline Silicon Carbide (3C) with Atomic Oxygen and Ozone
Authors: Varadachari Chandrika , Bhowmick Ritabrata , Ghosh Kunal
Published: December 2012

Thermodynamics of oxidation of crystalline silicon carbide (cubic form) by atomic oxygen (O) and ozone (O3) was derived to understand the thermodynamic stability of SiC in the upper atmosphere. Equilibrium constants and equilibrium partial pressures were computed for each of eight possible reactions of SiC with O and O3. Equilibrium activity diagrams were derived, showing the most stable oxidation products of SiC, represented in temperature-oxygen pressure (T-PO/O3) 2D diagrams. Programs were developed in Mathematica. The diagrams provide an understanding of the oxidation routes of SiC under changing levels of O/O3 and temperature, as encountered during reentry of space vehicles. At high levels of the volatiles, CO2, CO, and SiO and temperatures between 1000 and 1500 K, oxidation by atomic oxygen or ozone first produced SiO2 + C followed by SiO2 + CO and finally SiO2 + CO2. When volatiles were at very low pressures, the sequence of oxidation was SiO + CO followed by either SiO2 + CO or SiO + CO2 and finally SiO2 + CO2. Stability of SiC in ozone was much lower than in atomic oxygen. With both oxidants, the oxidation of the Si in SiC occurred prior to the oxidation of C. Implications for mechanisms of thermal protection are discussed.
How Far Do the Complaints of Patients with Parkinson’s Disease Reflect Motor Fluctuation? Quantitative Analysis Using a Portable Gait Rhythmogram
Authors: Utsumi Hiroya , Terashi Hiroo , Ishimura Yohei , Takazawa Tomoko , Okuma Yasuyuki , Yoneyama Mitsuru , Mitoma Hiroshi
Published: December 2012

In advanced-stage Parkinson’s disease (PD), motor fluctuation is a frequent and disabling problem. Assessment of motor fluctuation depends on patient’s subjective self-statement. We examined whether the subjective fluctuation matched the objective motor fluctuation defined by gait disorders. Using a new device, the portable gait rhythmogram, we recorded gait cadence and acceleration continuously over the 24-hour period in 54 patients with PD and 17 normal controls, for the quantitative evaluation of motor fluctuation. The patients were asked to estimate motor fluctuation every hour. In 44 of 54 patients, changes in the cadence were associated with simultaneous changes in acceleration. We examined the subjective fluctuation in these 44 patients who were confirmed to have motor fluctuation. Nineteen (82.7%) of 23 patients who felt no fluctuation showed distinct gait disorders. During off time, they walked with marked short or bradykinetic stepping. No matching changes were observed in either the cadence or acceleration in 11 (52.4%) of 21 patients who perceived motor fluctuation. No synchronization was noted in 30 (68.2%) of the 44 patients, between the times of subjectively assessed motor fluctuation and those of quantitative analysis of gait disorder. This discrepancy suggests that the objective continuous recording of the cadence and acceleration is necessary to understand motor fluctuation.
Itraconazole Niosomes Drug Delivery System and Its Antimycotic Activity against Candida albicans
Authors: Wagh Vijay D. , Deshmukh Onkar J.
Published: December 2012

Niosomes have potential applications in topical drug delivery system. The objective of the study was to formulate and evaluate the niosome of Itraconazole. Surfactant : cholesterol ratio and quantity of ethanol used were studied by applying factorial design. Formulated niosomes were evaluated for vesicle size, entrapment efficiency, drug release, skin permeation, and antimycotic activity. Vesicle size, entrapment efficiency, and drug release were markedly dependent on surfactant : cholesterol ratio and quantity of ethanol used. Permeation of the drug through the skin was affected by cholesterol content in formulation. Itraconazole niosome were having larger zone of inhibition than marketed formulation when activity was checked against C. albicans. Niosomes may be a promising carrier for topical delivery of Itraconazole especially due to their simple production.
Optimal Control of Diffusions with Hard Terminal State Restrictions
Authors: Seierstad Atle
Published: December 2012

A maximum principle is proved for certain problems of optimal control of diffusions where hard end constraints occur. The results apply to several dimensional problems, where some of the state equations involve Brownian motions, but not the equations corresponding to states being hard restricted at the terminal time.
SVM-Based Control System for a Robot Manipulator
Authors: Abdessemed Foudil
Published: December 2012

Real systems are usually non-linear, ill-defined, have variable parameters and are subject to external disturbances. Modelling these systems is often an approximation of the physical phenomena involved. However, it is from this approximate system of representation that we propose - in this paper - to build a robust control, in the sense that it must ensure low sensitivity towards parameters, uncertainties, variations and external disturbances. The computed torque method is a well-established robot control technique which takes account of the dynamic coupling between the robot links. However, its main disadvantage lies on the assumption of an exactly known dynamic model which is not realizable in practice. To overcome this issue, we propose the estimation of the dynamics model of the nonlinear system with a machine learning regression method. The output of this regressor is used in conjunction with a PD controller to achieve the tracking trajectory task of a robot manipulator. In cases where some of the parameters of the plant undergo a change in their values, poor performance may result. To cope with this drawback, a fuzzy precompensator is inserted to reinforce the SVM computed torque-based controller and avoid any deterioration. The theory is developed and the simulation results are carried out on a two-degree of freedom robot manipulator to demonstrate the validity of the proposed approach.
Data-Wave-Based Features Extraction and Its Application in Symbol Identifier Recognition and Positioning Suitable for Multi-Robot Systems
Authors: Liu Xilong , Qian Hanbo , Cao Zhiqiang , Zhou Chao , Yang Yuequan , Tan Min
Published: December 2012

In this paper, feature extraction based on data-wave is proposed. The concept of data-wave is introduced to describe the rising and falling trends of the data over the long-term which are detected based on ripple and wave filters. Supported by data-wave, a novel symbol identifier with significant structure features is designed and these features are extracted by constructing pixel chains. On this basis, the corresponding recognition and positioning approach is presented. The effectiveness of the proposed approach is verified by experiments.
Scolopendrellidae (Myriapoda, Symphyla) from the Afrotropics with descriptions of seven new species
Authors: Domínguez Camacho Miguel , VandenSpiegel Didier
Published: December 2012

Among the Scolopendrellidae belonging to the collection of Symphyla of the Royal Museum for Central Africa (Tervuren, Belgium), ten species were found and seven new species are described: Symphylella erecta sp. nov., S. fuko sp. nov., S. kalundu sp. nov., S. lubumbashi sp. nov., S. malagassa sp. nov., S. tanganyika sp. nov. and Remysymphyla spinosa sp. nov. SEM micrographs and additional information of the new species and also of Remysymphyla hova Aubry & Masson, 1952, Ribautiella zagnanadina Brölemann, 1926 and R. schoutedeni Hinschberger, 1954 are provided, which contributes to an easier determination of the afrotropical scolopendrellid species. The diagnosis of the genus Remysymphyla is discussed.
Childhood Asthma: Diagnosis and Treatment
Authors: van Aalderen Wim M.
Published: December 2012

Many children suffer from recurrent coughing, wheezing and chest tightness. In preschool children one third of all children have these symptoms before the age of six, but only 40% of these wheezing preschoolers will continue to have asthma. In older school-aged children the majority of the children have asthma. Quality of life is affected by asthma control. Sleep disruption and exercised induced airflow limitation have a negative impact on participation in sports and social activities, and may influence family life. The goal of asthma therapy is to achieve asthma control, but only a limited number of patients are able to reach total control. This may be due to an incorrect diagnosis, co-morbidities or poor inhalation technique, but in the majority of cases non-adherence is the main reason for therapy failures. However, partnership with the parents and the child is important in order to set individually chosen goals of therapy and may be of help to improve control. Non-pharmacological measures aim at avoiding tobacco smoke, and when a child is sensitised, to avoid allergens. In pharmacological management international guidelines such as the GINA guideline and the British Guideline on the Management of Asthma are leading.
Chromatin is an ancient innovation conserved between Archaea and Eukarya
Authors: Ammar Ron , Torti Dax , Tsui Kyle , Gebbia Marinella , Durbic Tanja , Bader Gary D , Giaever Guri , Nislow Corey
Published: December 2012

The eukaryotic nucleosome is the fundamental unit of chromatin, comprising a protein octamer that wraps ∼147 bp of DNA and has essential roles in DNA compaction, replication and gene expression. Nucleosomes and chromatin have historically been considered to be unique to eukaryotes, yet studies of select archaea have identified homologs of histone proteins that assemble into tetrameric nucleosomes. Here we report the first archaeal genome-wide nucleosome occupancy map, as observed in the halophile Haloferax volcanii. Nucleosome occupancy was compared with gene expression by compiling a comprehensive transcriptome of Hfx. volcanii. We found that archaeal transcripts possess hallmarks of eukaryotic chromatin structure: nucleosome-depleted regions at transcriptional start sites and conserved −1 and +1 promoter nucleosomes. Our observations demonstrate that histones and chromatin architecture evolved before the divergence of Archaea and Eukarya, suggesting that the fundamental role of chromatin in the regulation of gene expression is ancient.
Distinct gating mechanisms revealed by the structures of a multi-ligand gated K+ channel
Authors: Kong Chunguang , Zeng Weizhong , Ye Sheng , Chen Liping , Sauer David Bryant , Lam Yeeling , Derebe Mehabaw Getahun , Jiang Youxing
Published: December 2012

The gating ring-forming RCK domain regulates channel gating in response to various cellular chemical stimuli in eukaryotic Slo channel families and the majority of ligand-gated prokaryotic K+ channels and transporters. Here we present structural and functional studies of a dual RCK-containing, multi-ligand gated K+ channel from Geobacter sulfurreducens, named GsuK. We demonstrate that ADP and NAD+ activate the GsuK channel, whereas Ca2+ serves as an allosteric inhibitor. Multiple crystal structures elucidate the structural basis of multi-ligand gating in GsuK, and also reveal a unique ion conduction pore with segmented inner helices. Structural comparison leads us to propose a novel pore opening mechanics that is distinct from other K+ channels.
Reducing radar cross section by investigation electromagnetic materials
Authors: Komeylian S. , Hojjat-Kashani F.
Published: December 2012

Decreasing the Radar Cross Section (RCS) is investigated in electromagnetic materials, i.e. double-positive (DPS) , double-negative (DNG) , epsilon-negative (ENG) and mu-negative (MNG) materials. The interesting properties of these materials lead to a great flexibility in manufacturing structures with unusual electromagnetic characteristics. The valid conditions for achieving the transparency and gaining resonance for an electrically small cylinder are established, in this corresponding The effect of incidence direction on RCS inclusive of transparency and resonance conditions is also explored ,through computer simulations for an electrically small cylinder.
Review of Third and Fourth Re-Excision for Narrow or Positive Margins of Invasive and Intraductal Carcinoma
Authors: Subhas Gokulakkrishna , Shah Asha J. , Gupta Aditya , Cook Jonathan , Dubay Linda , Silapaswan Sumet , Kolachalam Ramachandra , Kestenberg William , Ferguson Lorenzo , Jacobs Michael J. , Goriel Yousif , Mittal Vijay K.
Published: December 2012

The trend in breast surgery has shifted toward breast conservation. We reviewed our third and fourth breast re-excision cases, with an analysis of various factors used in making this decision. A retrospective analysis identified 585 patients who underwent re-excision surgery for positive or close margins of invasive carcinoma or ductal carcinoma in situ (DCIS). Of these patients 75 (13%) and 17 (3%) underwent third and fourth re-excisions, respectively. The indication for a third re-excision was the presence of positive and/or close (≤1 mm) margins for invasive carcinoma or DCIS in 72/75 patients. A third re-excision was done 31 days (range 8–123 days) after the second re-excision. Re-excision of margins was done in 45 (60%) patients, whereas 30 (40%) patients underwent mastectomy. Residual tumor mandated a fourth re-excision in 17 patients, which was done 45 days (range 14–87 days) after the third surgery. Re-excision of margins was done in 6 patients, whereas 11 patients underwent mastectomy. Involved or close margins with DCIS were the most common indication for re-excision, accounting for 61/75 (82%) of third and 16/17 (94%) of fourth re-excisions. Histopathology revealed that 28/75 (37%) of third and 7/17 (41%) of fourth re-excision patients had no residual tumor. In conclusion, the majority of re-excisions was done for margins <1 mm. Lower rates of re-excision were noted in well-differentiated invasive carcinomas. A close or involved DCIS margin was more likely to lead to a third and even a fourth re-excision. The absence of residual tumors in 40% of patients undergoing third and fourth re-excisions calls for a review of margin guidelines for breast re-excision.
Clinical Importance of Surgical Treatment of Low Rectal Carcinoma in Anus-Preserving Procedure—an Analysis of 86 Cases
Authors: Hong-bing Liu , Xiao-peng Han , Wan-Kun Zhu , Lin Su , Xian-Kun Zhang
Published: December 2012

We investigated the methods and experiences of an anus-preserving procedure in curative resection of low rectal carcinoma. Eighty-six patients with low rectal carcinoma underwent Dixon's procedure with device assistance. Patients were then observed for the effects of operation. The operation was successful in all patients. Pathologic examination of specimens revealed negative margins. Complications such as anastomotic leakage were found in 7 cases. All patients recovered well. Device assistance may contribute to the successful performance of anus-preserving procedure in low rectal carcinoma. Whether the anus can be preserved or not depends on the accurate measurement of the distal length of the rectum. A meticulous hemostasis and avoidance of tension on the stoma are key measures for avoiding anastomotic leakage.
A Meta-analysis of Outcomes After Routine Aspiration of the Gallbladder During Cholecystectomy
Authors: Siddiqui M. R. S. , Sajid M. S. , Nisar A. , Ali H. , Zaborszky A. , Hasan F.
Published: December 2012

We conducted a meta-analysis of published literature comparing outcomes after aspirating (ASP) the gallbladder versus nonaspiration (NASP). Electronic databases were searched from January 1985 to November 2009. A meta-analysis was performed to obtain a summative outcome. Two randomized, controlled trials involving 360 patients were analyzed. A total of 180 patients were in the ASP group, and 180 were in the NASP group. There was no significant increase in operative time in the ASP group compared with the NASP group [random-effects model: standardized mean difference, −0.72; 95% confidence interval (CI), −2.16, 0.71; z  =  0.99; df  =  1; P  =  0.32], but there was significant heterogeneity among trials (Q  =  42.4; P < 0.001; I2  =  98%). Patients undergoing ASP were less likely to have a gallbladder perforation [random-effects model: risk ratio (RR), 0.42; 95% CI, 0.19, 0.96; z  =  2.05; df  =  1; P < 0.05], but no difference was found regarding the loss of gallstones (random-effects model: RR, 1.33; 95% CI, 0.30, 5.85; z  =  0.38; df  =  1; P  =  0.70). No difference was seen for liver bed bleeding (P  =  0.43) or overall 30-day infection rates (P  =  0.66). After aspiration, gallbladder perforation rates may be lower. This does not appear to translate into decreased loss of gallstones or infection rates. There was no significant difference between techniques in blood loss from the liver bed. Further randomized, controlled trials and follow-up studies are required to confirm these results and to establish long-term sequelae.
Pathology Studies of Combined Radical Resection of Seminal Vesicle in the Treatment of Rectal Cancer
Authors: Komori Koji , Hirai Takashi , Kanemitsu Yukihide , Shimizu Yasuhiro , Sano Tsuyoshi , Ito Seiji , Senda Yoshiki , Misawa Kazunari , Ito Yuichi , Kato Tomoyuki
Published: December 2012

To inhibit local recurrence of rectal cancer, it is very important to ensure that there is a sufficient circumferential resection margin. We evaluated pathology studies of combined radical resection of seminal vesicles in the treatment of rectal cancer. We analyzed data from 7 cases of combined radical resection of the seminal vesicle in the treatment of rectal cancer; we also analyzed data from 35 control cases without seminal vesicle resection. The circumferential resection margin averaged 5.97 mm for cases that had combined radical resection of the seminal vesicle, and this was significantly longer than for cases without resection (P < 0.001). Local recurrence was not seen in cases that had combined radical resection of the seminal vesicle, whereas 3 cases (5.9%) occurred in the group that did not undergo resection. Combined radical resection of the seminal vesicle in patients with rectal cancer ensures that the distance of the circumferential resection margin is sufficient to inhibit local recurrence.
Experience of Distal Gastrectomy By Minilaparotomy With Laparoscopic-Assistance for Nonoverweight Patients With T1N0-1 Gastric Cancer
Authors: Ishida Hideyuki , Ishiguro Toru , Okada Norimichi , Kumamoto Kensuke , Ishibashi Keiichiro , Miyazaki Tatsuya , Haga Norihiro
Published: December 2012

To evaluate the usefulness of laparoscopic assistance for curative distal gastrectomy by minilaparotomy, 19 patients (body mass index ≤25.0 kg/m2) with T1N0-1 gastric cancer who underwent distal gastrectomy with a minilaparotomy (skin incision ≤7 cm) with laparoscopic assistance (LA (+) group) were compared with 19 historic controls who underwent equivalent surgery by minilaparotomy without laparoscopic assistance (LA (−) group). The percentage of patients with blood loss more than 300 mL tended to be lower in the LA (+) group (5.3% versus 31.6%, P  =  0.09). The first flatus passage was earlier (P  =  0.04), serum C-reactive protein levels on postoperative day 1 were lower (P  =  0.04), and white blood cell counts on postoperative day 1 tended to be lower (P  =  0.07) in the LA (+) group. Minilaparotomy with laparoscopic assistance seems to be less invasive compared with pure minilaparotomy. This procedure is considered to be a simple alternative to standard laparoscopic-assisted distal gastrectomy in selected patients with T1N0-1 gastric cancer.
Intestinal Pneumatosis in Which CT Colonography Was of Significant Diagnostic Value: Case Report
Authors: Shimada Ryu , Hayama Tamuro , Yamazaki Norihito , Akahane Takuya , Horiuchi Atushi , Shibuya Hajime , Yamada Hideki , Ishihara Soichiro , Nozawa Keijiro , Matsuda Keiji , Watanabe Toshiaki
Published: December 2012

Intestinal pneumatosis refers to the presence of gas in the gastrointestinal wall. It is often difficult to clinically differentiate this condition from gastrointestinal perforation, sometimes resulting in emergency surgery. Imaging studies are important to establish the differential diagnosis. However, there have been few studies showing the efficacy of computed tomography (CT) colonography in diagnosing pneumatosis. We report a case of intestinal pneumatosis in which CT colonography was of significant diagnostic value. A 43-year-old man was referred to our hospital for a detailed investigation of multiple submucosal tumor-like lesions associated with multiple pneumatosis from the cecum to the ascending colon. These lesions were revealed by colonoscopy performed in another hospital on May 21, 2008. Abdominal 3-dimensional CT showed multiple pneumatic lesions from the cecum to the ascending colon, and the patient was diagnosed as having intestinal pneumatosis. The patient is being followed conservatively because he is asymptomatic.
Torquated Giant Appendix Epiploica Mimicking Intraperitoneal Liposarcoma: Report of a Case
Authors: Jeanmonod Pascal , Sperling Jens , Seidel Roland , Richter Sven , Kollmar Otto , Schuld Jochen
Published: December 2012

A 49-year-old woman presented with acute abdominal pain in the right iliac fossa in our emergency department. Pain was abrupt in onset and severely colicky in nature. Abnormal laboratory values included a C-reactive protein of 75 mg/L and a CA-125 of 70.3 U/mL. White blood cell count was normal. Abdominal computed tomography (CT) scan revealed an inhomogeneous mass of 9.5 × 3.5 × 5.5 cm in diameter close to the appendix vermiformis and the sigmoid colon. Because of the clinical symptoms of an acute abdomen an explorative laparotomy was performed. Intraoperatively a pedunculated tumor beginning at the serosa of the sigmoid colon was found. The appendix was unremarkable. The macroscopic aspect as well as the backtable incision of the tumor was suspicious of an intraperitoneal liposarcoma. Rapid section and histopathologic examination revealed necrotic fat tissue without any malignancy. The patient was discharged from the hospital 7 days after the operation with normal laboratory parameters and without further complication. When epiploic appendagitis is evident as a big tumor mass in addition to clinical symptoms of an acute abdomen and elevated tumor markers, surgical exploration is mandatory.
The Progression Potential of Peritoneal Dissemination Nodules From Gastrointestinal Tumors
Authors: Yamauchi Hayato , Suto Toshinaga , Kigure Wakako , Morita Hiroki , Kato Toshihide , Yajima Reina , Fujii Takaaki , Yamaguchi Satoru , Tsutsumi Soichi , Asao Takayuki , Kuwano Hiroyuki
Published: December 2012

It is necessary to examine the characteristics of the dissemination nodules to establish a therapeutic strategy for peritoneal dissemination from digestive malignancy. Ki-67 expression as a proliferation marker in peritoneal dissemination nodules was investigated. The subjects were 15 patients with gastrointestinal cancers who underwent resection of the primary tumor and disseminated nodules. The expression of Ki-67 in both primary tumor and peritoneal dissemination nodule from each patient was evaluated by immunohistochemistry. Ki-67 labeling index in the original tumor was higher than that in the disseminated nodule in 13 of 15 patients (P < 0.0001). The mean value of Ki-67 labeling index was 42.2% in the 15 original tumors and 18.7% in the 15 disseminated nodules. Proliferative activity in the disseminated nodules was lower than that in the primary tumors. Further examination about characteristics of cancer dissemination is needed to treat patients with peritoneal metastasis.
Liver Hemorrhage Due to Idiopathic Peliosis Hepatis Successfully Treated With Hepatic Artery Embolization
Authors: Suzuki Shigemasa , Suzuki Hideki , Mochida Yasushi , Hirai Hanako , Yoshida Takeshi , Ide Munenori , Tani Masachika , Shimura Tatsuo , Morinaga Nobuhiro , Ishizaki Masatoshi , Kuwano Hiroyuki
Published: December 2012

Peliosis hepatis is an extremely rare condition that may cause fatal hepatic hemorrhage and liver failure. We report a case of liver hemorrhage due to idiopathic peliosis hepatis. A 60-year-old woman was admitted to our hospital with slight right hypochondriac pain. She went into hemorrhagic shock, and computed tomography (CT) showed multiple low-density areas in the right liver with massive subcapsular blood collection. Selective transfemoral arteriography of the celiac artery revealed no signs of vascular malformation or tumor stain, but showed signs of pooling in the right posterior segmental artery. The artery was embolized with particles of gelatin sponge, and hemostatic control was successful. Although peliosis hepatis is extremely rare, the diagnosis is significant because of its urgent clinical status, and transarterial embolization is a useful and minimally invasive procedure for liver hemorrhage due to peliosis hepatis.
Recovery of Upper Gastrointestinal Bowel Movement After Rectosigmoid Cancer Surgery: A Pilot Transit Analysis
Authors: Matsuoka Hiroyoshi , Maeda Koutarou , Katsuno Hidetoshi , Tsunoda Akira , Koda Keiji , Ohge Hiroki , Oya Masatoshi , Yoshioka Kazuhiko , Imazu Yoshihiro , Masaki Tadahiko
Published: December 2012

Postoperative gastrointestinal bowel transit right after colorectal resection has not yet been clarified. Thirty patients with rectosigmoid cancer were treated in this pilot study. The nasogastric tube was removed on the first postoperative day. One Sitzmarks capsule was given to each patient on the second postoperative day. Abdominal X-rays were taken at 3, 6, 8, 24, 48, and 72 hours after capsule intake. Distribution of the remaining Sitzmarks capsules were counted on X-ray films to clarify postoperative gastrointestinal movement after bowel resection. All Sitzmarks capsules were observed in the stomach at 3 and 6 hours after capsule intake. At 8 hours (second postoperative day), the Sitzmarks capsules were distributed from the stomach to the small intestine. Sitzmarks capsules were distributed in the right side colon at 24 hours (third postoperative day) after intake. Although the main distribution was still in the right side colon, several patients had evacuations accompanied by the disappearance of the Sitzmarks capsules. In 50% of the patients, it took approximately 72 hours (fifth postoperative day) for the first defecation after intake of the capsules. However, the Sitzmarks capsules remained mainly in the right side colon. Eight hours after intake, the majority of the Sitzmarks capsules shifted to the small intestine. Therefore, medication or feeding should be safely possible starting on the second postoperative day. There was no particular impact of bowel resection on upper gastrointestinal transit in patients with rectosigmoid cancer.
Steroid-Responsive Myorhythmia in Pectoralis Muscles
Authors: Zhao Bing , Zhao Cuiping , Zhao Yuying
Published: July 2024

This case report describes a patient experiencing involuntary contractions in his right pectoralis muscles with anti-Tr antibodies in his serum, which is characteristic of myorhythmia.
Ghost Horizons: Scaffold and Syntax
Authors: Goché Oliver G , Goché Peter P
Published: July 2024

An empty granary in Iowa proves to be an experimental laboratory for immersive performative experiences and the manifestation of ghostly apparitions and ideas. The derelict building is porous and permeable, exhibiting a certain uncanniness through the shifting register of haunting vicissitudes which can be projected on, cross‐pollinated with, visually explored, touched, heard and marvelled at. Artist and designer Oliver G Goché and architect Peter P Goché take us through some of these ethereal vistas and environments.
Improving Stability, Crystallinity, and Photo‐Responsiveness of Supramolecular Frameworks by Surface Polymerization
Authors: Yang Tao , Li Xue‐Mei , Liu Yang , Wei Chao , Gu Chen , Zuo Mingrui , Guo Tianyu , Liu Guoliang , Ding Lifeng , Liu Xiao‐Qin , Sun Lin‐Bing
Published: July 2024

Metal–organic cage‐based photo‐responsive supramolecular frameworks (PSMFs) with permanent porosity have gained attention for their modular properties, controllable functionality, and light‐induced reversible responsiveness. However, their high porosity and photo‐responsive efficiency are often compromised due to poor structural stability upon solvent removal, limiting their potential applications. Here, a solution to overcome this challenge by employing a surface polymerization strategy using isophorone diisocyanate (IDI) to stabilize PSMF (PCC‐20t) is presented. This approach results in the composite of PCC‐20t@PolyIDI, which preserves crystallinity and permanent high‐porosity while avoiding structural collapse commonly observed in highly porous supramolecular frameworks. Moreover, compared to activated PCC‐20t, PCC‐20t@PolyIDI exhibits an 18.6‐fold increase in specific surface area. Remarkably, the structural variability of PCC‐20t@PolyIDI can be observed in the photo‐regulation behavior of CO2 capacity under the irradiation of vis‐ and UV‐light, showing a 27.9% change in adsorption amount for CO2 which is significantly higher than that of the activated PCC‐20t with 7.0% for CO2. Grand Canonical Monte Carlo simulations demonstrate the light‐regulated adsorption performance is attributed to the configuration transformation of azobenzene from trans‐ to buckling state. The findings may pave the way for stabilizing high‐porosity materials to simultaneously meet demands for high‐porosity and photo‐responsive efficiency.
Optical Probe of Magnetic Ordering Structure and Spin‐Entangled Excitons in Mn‐Substituted NiPS3
Authors: Lee Je‐Ho , Lee Seungyeol , Choi Youngsu , Gries Lukas , Klingeler Rüdiger , Raju Kalaivanan , Ulaganathan Rajesh Kumar , Sankar Raman , Seong Maeng‐Je , Choi Kwang‐Yong
Published: July 2024

In van der Waals magnets, the interplay between magneto‐excitonic coupling and optical phenomena opens avenues for directly probing magnetic ordering structures, manipulating excitonic properties through magnetic fields, and exploring quantum entanglement between electronic and magnetic states. Notably, NiPS3 stands out for its capacity to host spin‐entangled excitons, where the excitonic states are intricately tied with the material's spin configuration. Herein, it is experimentally showcased that the spin‐entangled excitons can be utilized for detecting the magnetic easy axis in Ni1‐xMnxPS3 (x = 0–0.1). The end members of this series exhibit distinct magnetic ordering patterns and easy axes: zigzag ordering with magnetic moments aligned along the a‐axis for NiPS3 versus Néel ordering with the out‐of‐plane easy axis for MnPS3. By combining angle‐resolved exciton photoluminescence with magnetic susceptibility measurements, it is observed that the magnetic easy axis rotates away from the local spin chain direction with increasing Mn content. Moreover, through a comprehensive thermal and substitution study, it is demonstrated that the energy and lifetime of spin‐entangled excitons are governed by two spin‐flip processes and are drastically influenced by disparate electronic states. These findings not only provide optical means to map out magnetic ordering structures but also offer insights into decoherence processes in spin‐exciton entangled states.
Heat Transport at Silicon Grain Boundaries
Authors: Isotta Eleonora , Jiang Shizhou , Bueno‐Villoro Ruben , Nagahiro Ryohei , Maeda Kosuke , Mattlat Dominique Alexander , Odufisan Alesanmi R. , Zevalkink Alexandra , Shiomi Junichiro , Zhang Siyuan , Scheu Christina , Snyder G. Jeffrey , Balogun Oluwaseyi
Published: July 2024

Engineering microstructural defects, like grain boundaries, offers superior control over transport properties in energy materials. However, technological advancement requires establishing microstructure‐property relations at the micron or finer scales, where most of these defects operate. Here, the first experimental evidence of thermal resistance for individual silicon grain boundaries, estimated with a Gibbs excess approach, is provided. Coincident site lattice boundaries exhibit uniform excess thermal resistance along the same boundary, but notable variations from one boundary to another. Boundaries associated with low interface energy generally exhibit lower resistances, aligning with theoretical expectations and previous simulations, but several exceptions are observed. Transmission electron microscopy reveals that factors like interface roughness and presence of nanotwinning can significantly alter the observed resistance, which ranges from ∼0 to up to ∼2.3 m2K/GW. In stark contrast, significantly larger and less uniform values ‐ from 5 to 30 m2K/GW ‐ are found for high‐angle boundaries in spark‐plasma‐sintered polycrystalline silicon. Further, finite element analysis suggests that boundary planes that strongly deviate from the sample vertical (beyond ∼45°) can show up to 3‐times larger excess resistance. Direct correlations of properties with individual defects enable the design of materials with superior thermal performance for applications in energy harvesting and heat management.
Enhancing Photocatalytic Activity for Solar‐to‐Fuel Conversion: A Study on S‐Scheme AgInS2/CeVO4@Biocharx Heterojunctions
Authors: Zhang Junqiang , Ling Weikang , Li Aohua , Ma Jiliang , Hong Min , Sun Runcang
Published: July 2024

Rare earth vanadates are promising for solar‐to‐fuel conversions, yet their photocatalytic efficiency is limited by the substantial recombination of photo‐generated carriers. Constructing heterojunctions is recognized as an effective approach to improving charge carrier separation in vanadates. Nonetheless, inefficient charge transfer often results from the poor quality of interfaces and non‐directional charge transfer within these heterojunctions. Herein, an S‐scheme AgInS2/CeVO4@Biocharx (AIS/CV@Cx) heterojunction photocatalyst is designed and synthesized through a straightforward freeze‐drying and calcination three‐step process, aimed at photocatalytic co‐production of xylonic acid and carbon monoxide (CO) from xylose. The AIS/CV@C2 heterojunction achieves an optimal yield of 67.74% for xylonic acid and a CO release of 29.76 µmol from xylose. The enhanced photocatalytic performance of the AIS/CV@C2 heterojunction is attributed to three key factors: I) the high‐quality interface and intimate contact within the AIS/CV@C2 heterojunction significantly reduce undesirable carriers recombination, II) the staggered band structures and directed carriers transfer in the AIS/CV@C2 heterojunction notably improve spatial carriers separation/migration, and III) the incorporation of biochar boosts the conductivity of the AIS/CV@C2 heterojunction. This work presents a straightforward yet effective method for fabricating vanadate heterojunctions, highlighting the importance of quality interfacial contact and directed charge transfer in amplifying photocatalytic performance.
Microwave‐Responsive Nanoplatform with Robust ROS Generation and Inhibiting Effects of Two‐Component System and Quorum Sensing for the Treatment of MRSA‐Induced Osteomyelitis
Authors: Cheng Hao , Yang Yongqiang , Wang Yueyue , Guo Jiqiang , Jiao Xiong , Huang Di , An Meiwen , Yao Xiaohong , Chu Paul K. , Zhang Xiangyu
Published: July 2024

The hypoxic environment of deep tissue and the weak energy of microwave (MW) are still the major limitations of MW catalytic therapy. In this work, an MW‐responsive nano‐platform consisting of an Mn‐doped porphyrin metal–organic framework loaded with   calcium peroxide (Mn0.1PCC) is designed to regulate the microenvironment of the injection site and enhance the generation of reactive oxygen species. The excellent MW absorbing properties of Mn0.1PCC improve the Fenton reaction between hydrogen peroxide formed by the hydrolysis of calcium peroxide and released Mn2+ generating more hydroxyl radicals under MW. This process does not consume the oxygen substrate and even produces oxygen to improve the hypoxic environment. Therefore, at a low and safe concentration (125 µg mL−1), the antibacterial rate of Mn0.1PCC against 4 × 108 CFU mL−1 of methicillin‐resistant Staphylococcus aureus (MRSA) after MW irradiation for 15 min is 99.71% ± 0.18%. Mn0.1PCC, upon exposure to MW, prevents the recurrence of bacterial infections and overcomes drug resistance by inhibiting quorum sensing and the two‐component system of MRSA. It can also induce macrophage M1 polarization, up‐regulate the pro‐inflammatory factor tumor necrosis factor‐α, and enhance the phagocytosis of macrophage to bacteria. This strategy provides insights into the development of high‐performance MW‐responsive nanocomposites for the treatment of infections in deep tissues.
Failure Mechanisms and Strategies Toward Flexible Zinc‐Air Batteries
Authors: Wang Hengwei , Kang Lingling , Wang Keliang , Wei Manhui , Pei Pucheng , Zuo Yayu , Liang Bin
Published: July 2024

Flexible zinc‐air batteries (FZABs) have emerged as a promising alternative to lithium‐ion batteries in flexible electronic devices due to the advantages of excellent mechanical properties, high energy density, and notable safety. However, the unclear causes of performance degradation and failure mechanisms of FZABs significantly impede their commercialization. Therefore, extensive research is needed to fully reveal the factors and mechanisms responsible for the performance decline of FZABs. In this review, the failure mechanisms of FZABs' key components, including the Zn anode, solid electrolyte, catalyst air cathode, and electrolyte/electrode interface are analyzed and discussed. To promote further research and development of FZABs, a series of challenges and corresponding strategies are summarized and analyzed. Finally, the future development of FZABs is envisioned. This paper aims to comprehensively elucidate the failure mechanisms of FZABs, guide the development of high‐performance FZABs, and thus promote their commercialization.
High Modulus Na2SiO3‐Rich Solid Electrolyte Interphase Enable Long‐Cycle and Energy‐Dense Sodium Metal Battery
Authors: Yang Bin , Yang Ziqiang , Zhang Xueqian , Zhao Ya , Wang Youyu , Chen Jiahao , Wang Sen , Zhao Qing , Hou Zhiguo
Published: July 2024

Sodium metal battery is considered as one of the most promising energy storage/conversion devices due to their high energy density, and abundant sodium reserves. However, its development is hampered by the limited metallic utilization and detrimental sodium dendrite growth ascribed to the unstable, and fragile solid electrolyte interphase (SEI). Here, the high stable and modulus SEI is constructed with a component of a thin and dense layer of high Na‐ion conductive Na2SiO3. It is in situ formed by the reaction between sodium anode and fish‐skin structure separator, which exhibits a 3D porous polyvinylidene fluoride‐based framework embedded with thin and robust vermiculite sheets. The robust interphase cannot only suppress sodium dendrite growth but also enable high energy density with small interphase‐consumed Na ions in anode‐less batteries. Accordingly, the as‐assembled NaNi1/3Fe1/3Mn1/3O2//Na cell shows 83% capacity retention after 5000 cycles at a rate of 5 °C. Moreover, the proof‐of‐concept pouch cells deliver an energy density of 205 Wh kg−1 (based on the total mass of the battery), and high safety (not catching fire after punctured) under anode‐less condition (with a low negative/positive capacity ratio of ≈2.1).
Recent Advancements and Challenges in High‐Power Thulium‐Doped Laser
Authors: Sohail Muhammad Tahir , Li Bowen , Guo Chunyu , Younis Muhammad , Shareef Maria , Abdullah Muhammad , Yan Peiguang
Published: July 2024

High‐power all‐fiber thulium lasers have gained considerable interest in recent times due to their distinct characteristics and versatile applications in the medical and industrial sectors. This review article presents a comprehensive examination of the advancements and challenges in this field. It begins with an overview of thulium‐doped silica fiber, which is a critical component for high‐power lasers operating at the 2 µm (micrometer) wavelength band. The research progress of essential high‐power thulium laser sources, including continuous‐wave (CW), quasi‐continuous wave (QCW), and pulsed lasers, is then thoroughly analyzed, highlighting their respective strengths and limitations. Additionally, the diverse applications of high‐power thulium fiber lasers in medical and industrial domains are summarized. Furthermore, the article emphasizes the current challenges in the advancement of high‐power thulium‐doped fiber lasers (TDFLs) and outlines potential avenues for future development. Despite TDFLs being the predominant laser source in lithotripsy and material processing applications, optimizing their performance and expediting further progress in thulium laser technology remain crucial objectives. This review article aims to provide valuable insights for researchers, engineers, and professionals working in the field of high‐power fiber lasers operating at 2 µm.
Therapeutic Targeting Tongue Squamous Cell Carcinoma via ICAM1 Antibody‐Drug Conjugates in Preclinical Models
Authors: Ma Letao , Xu Yanzhi , Yang Yuxuan , Yang Teng , Dai Yujie , Shimura Takaya , Sha Chulin , Li Xinfang , Fang Jianmin , Zheng Weihui , Lu Ye , Guo Peng
Published: July 2024

To date, the treatment options for metastatic and recurrent tongue squamous cell carcinoma (TSCC) remain limited due to the lack of effective drug targets and therapeutics. Here the identification of ICAM1 is reported as a TSCC target candidate for the development of antibody‐drug conjugate (ADC), an emerging class of targeted therapeutics. An unbiased and quantitative screening of a panel of 69 TSCC cell surface antigens is first performed that identifies ICAM1 as the most abundant hit. The overexpression level of ICAM1 is validated in 26 TSCC clinical specimens and four cell lines along with genomic information of 127 TSCC patients from the TCGA database. Based on this new target, the anti‐TSCC efficacy of ICAM1‐targeted ADCs featuring two payloads is evaluated of different mechanisms of action: MMAE and DXd. Both ADCs selectively and potently ablate TSCC tumors in the established SAS cell line and patient‐derived xenograft (PDX) models. The findings strongly support ICAM1 as a promising ADC target candidate for TSCC therapy.
A Convoy of Magnetic Millirobots Transports Endoscopic Instruments for Minimally‐Invasive Surgery
Authors: Jeong Moonkwang , Tan Xiangzhou , Fischer Felix , Qiu Tian
Published: July 2024

Small‐scale robots offer significant potential in minimally invasive medical procedures. Due to the nature of soft biological tissues, however, robots are exposed to complex environments with various challenges in locomotion, which is essential to overcome for useful medical tasks. A single mini‐robot often provides insufficient force on slippery biological surfaces to carry medical instruments, such as a fluid catheter or an electrical wire. Here, for the first time, a team of millirobots (TrainBot) is reported to generate around two times higher actuating force than a TrainBot unit by forming a convoy to collaboratively carry long and heavy cargos. The feet of each unit are optimized to increase the propulsive force around three times so that it can effectively crawl on slippery biological surfaces. A human‐scale permanent magnetic set‐up is developed to wirelessly actuate and control the TrainBot to transport heavy and lengthy loads through narrow biological lumens, such as the intestine and the bile duct. The first electrocauterization performed by the TrainBot is demonstrated to relieve a biliary obstruction and open a tunnel for fluid drainage and drug delivery. The developed technology sheds light on the collaborative strategy of small‐scale robots for future minimally invasive surgical procedures.
Strukturaufklärung einer metagenomischen Urethanase und Verbesserung des Hydrolyseprofils durch Protein Engineering
Authors: Bayer Thomas , Palm Gottfried J. , Berndt Leona , Meinert Hannes , Branson Yannick , Schmidt Louis , Cziegler Clemens , Somvilla Ina , Zurr Celine , Graf Leonie G. , Janke Una , Badenhorst Christoffel P. S. , König Stefanie , Delcea Mihaela , Garscha Ulrike , Wei Ren , Lammers Michael , Bornscheuer Uwe T.
Published: July 2024

Während Kunststoffe wie Polyethylenterephthalat (PET) bereits effizient durch die Aktivität von Hydrolasen abgebaut werden können, sind andere synthetische Polymere wie Polyurethane (PUs) und Polyamide (PAs) weitgehend resistent gegenüber einem biologischen Abbau. In dieser Studie lösten wir die erste Kristallstruktur der metagenomischen Urethanase UMG‐SP‐1, identifizierten hochflexible Loopregionen, die Reste des aktiven Zentrums enthalten, und untersuchten insgesamt 20 potenzielle Hotspots mittels Sättigungsmutagenese. Die durch Protein Engineering erzeugten Einzelmutanten wiesen eine fast 3‐ bzw. 8‐fach verbesserte Aktivität gegenüber hochstabilen N‐Arylurethan‐ und Amidbindungen auf. Darüber hinaus konnte die Freisetzung der entsprechenden Monomere aus einem thermoplastischen Polyester‐PU und einem PA (Nylon 6) durch die Aktivität einer einzigen, metagenomischen Urethanase nach kurzer Inkubationszeit nachgewiesen werden. Dadurch konnte das Hydrolyseprofil von UMG‐SP‐1 über die bekannten niedermolekularen Carbamate hinaus erweitert werden und erschließt so neue Möglichkeiten für den enzymatischen Abbau und das Recycling von Kunststoffen und Plastikabfällen. Damit unterstützt diese Studie Bemühungen um die Verbesserung einer Kreislaufwirtschaft für synthetische Polymere.
Cycloadditionen von Diazoalkenen mit P4 und tBuCP: Ein Zugang zu Diazaphospholen
Authors: Hauer Sebastian , Reitz Justus , Koike Taichi , Hansmann Max M. , Wolf Robert
Published: July 2024

Reaktionen von Diazoalkenen mit tert‐Butylphosphaalkin (tBuCP) und weißem Phosphor (P4) führen zu neuen Phosphorheterocyclen, 3H‐1,2,4‐Diazamonophospholen und 1,2,3,4‐Diazadiphospholen. Die erhaltenen Verbindungen sind seltene Beispiele für neutrale Heterophosphole. Der Bildungsmechanismus der formalen (3+2)‐Cycloadditionsprodukte wurde quantenchemisch berechnet und die elektronischen Strukturen analysiert. Die neuen Phosphole bilden strukturell vielfältige Koordinationsverbindungen mit Übergangsmetallen und Hauptgruppenelementen. Angesichts der wachsenden Anzahl stabiler Diazoalkene bietet diese Arbeit einen unmittelbaren Zugang zu neutralen Aza(di‐)phospholen als neue Ligandenklasse.
Structural Elucidation of a Metagenomic Urethanase and Its Engineering Towards Enhanced Hydrolysis Profiles
Authors: Bayer Thomas , Palm Gottfried J. , Berndt Leona , Meinert Hannes , Branson Yannick , Schmidt Louis , Cziegler Clemens , Somvilla Ina , Zurr Celine , Graf Leonie G. , Janke Una , Badenhorst Christoffel P. S. , König Stefanie , Delcea Mihaela , Garscha Ulrike , Wei Ren , Lammers Michael , Bornscheuer Uwe T.
Published: July 2024

While plastics like polyethylene terephthalate can already be degraded efficiently by the activity of hydrolases, other synthetic polymers like polyurethanes (PUs) and polyamides (PAs) largely resist biodegradation. In this study, we solved the first crystal structure of the metagenomic urethanase UMG‐SP‐1, identified highly flexible loop regions to comprise active site residues, and targeted a total of 20 potential hot spots by site‐saturation mutagenesis. Engineering campaigns yielded variants with single mutations, exhibiting almost 3‐ and 8‐fold improved activity against highly stable N‐aryl urethane and amide bonds, respectively. Furthermore, we demonstrated the release of the corresponding monomers from a thermoplastic polyester‐PU and a PA (nylon 6) by the activity of a single, metagenome‐derived urethanase after short incubation times. Thereby, we expanded the hydrolysis profile of UMG‐SP‐1 beyond the reported low‐molecular weight carbamates. Together, these findings promise advanced strategies for the bio‐based degradation and recycling of plastic materials and waste, aiding efforts to establish a circular economy for synthetic polymers.