bluuebunny/crossref_metadata_2025 huggingface dataset:
The possible involvement of protein phosphatase 1 in thrombin‐induced Ca2+ influx of human platelets
Authors: Murata Kouhei , Sakon Masato , Kambayashi Jun‐Ichi , Yukawa Masao , Yano Yoshiko , Fujitani Kazumasa , Kawasaki Tomio , Shiba Eiichi , Mori Takesada
Published: June 2014

Protein phosphatase 1 is considered to be involved in thrombin‐induced platelet activation (Murata et al., Biochem Int 26:327–334, 1992). To clarify the mechanism, we examined the effects of protein phosphatase 1 and 2A inhibitors (calyculin A, tautomycin, okadaic acid) on Ca2+ influx. In the presence of 1 mM Ca2+, thrombin‐ (0.1 U/ml) induced platelet aggregation and ATP release were inhibited by calyculin A, while this inhibitory effect was abolished in the absence of Ca2+ (EGTA 1 mM). Furthermore, thrombin‐induced Mn2+ influx but not intracellular Ca2+ mobilization was inhibited by calyculin A in a dose‐related manner. Calyculin A also blocked the ongoing Ca2+ influx when added 3 min after thrombin stimulation. Similar inhibitory effects were observed with okadaic acid and tautomycin in the same potency sequence as the reported one for protein phosphatase 1 (calyculin A > tautomycin > okadaic acid). These results suggest that the anti‐platelet effects of phosphatase inhibitors are due to the inhibition of Ca2+ influx and that protein phosphatase 1 plays a key role in the regulation of receptor operated Ca2+ channel of human platelets.
Derivatives of 4‐amino‐3,6‐disulfonato‐1, 8‐naphthalimide inhibit reverse transcriptase and suppress human and feline immunodeficiency virus expression in cultured cells
Authors: Rideout Darryl , Schinazi Raymond , Pauza C. David , Lovelace Kathleen , Chiang Lin‐Chang , Calogeropoulou Theodora , McCarthy Michael , Elder John H.
Published: June 2014

We have developed a series of 4‐amino‐3,6‐disulfonato‐1,8‐naphthalimide (ADSN) derivatives in an attempt to create nontoxic compounds effective against lentivirus infections. The ADSN derivative Lucifer Yellow CH ([N‐(hydra zinocarbonyl)amino]‐4‐amino‐3,6‐disulfonato‐1,8‐naphthalimide) (LYCH) was chosen as a parent compound because of its low toxicity in vivo and in vitro and its tendency to accumulate in monocyte/macrophages, a major reservoir for lentiviruses in vivo. Several ADSN derivatives inhibited reverse transcriptases (RTs) from human immunodeficiency virus type 1 (HIV‐1) and feline immunodeficiency virus (FIV). Viral expression in HIV‐infected human peripheral blood mononuclear cells was inhibited by noncytotoxic concentrations of two ADSN derivatives, designated A4 (biphenyl‐4,4′‐dicarboxaldehyde, Lucifer Yellow CH monohydrazone; EC50 = 29 μM after 6 days) and H4 (biphenyl‐4,4′‐dicarboxaldehyde, Lucifer Yellow CH dihydrazone; EC50 = 5.61 μM). A4 effectively suppressed the expression of FIV in infected Crandall feline kidney fibroblasts (CRFK) at 46.2 μM, reducing the RT levels by 97% after 19 days under conditions allowing direct cell‐to‐cell transmission of the virus. The viability of drug‐treated FIV‐infected CRFK cells increased significantly in the presence of A4 relative to the viability of untreated virus‐infected cells. In contrast to A4 and H4, LYCH (which lacks the appended aromatic rings characteristic of A4 and H4) had no inhibitory effects on either virus and did not inhibit RT ex vivo. However, flow cytometry studies showed that both A4 and LYCH accumulate in two cell types that can support lentiviral infections: U937 human monocytic leukemic cells that have been induced to differentiate by using tetradecanoyl phorbol acetate, and CRFK cells.
Fatty acyl‐CoA binding activity of the nuclear thyroid hormone receptor
Authors: Li Qiulin , Yamamoto Naoki , Morisawa Seiji , Inoue Akira
Published: June 2014

Long‐chain fatty acids and their acyl‐CoA esters are potent inhibitors of nuclear thyroid hormone (T3) receptor in vitro. In the present study, we obtained evidence for acyl‐CoA binding activity in the nuclear extract from rat liver. The activity sedimented at a position (3.5 S) identical with that of the T3 receptor, and the two activities sedimented together. Similarly, they coeluted on DEAE‐Sephadex. After partial purification of the receptor, it was again inhibited strongly by acyl‐CoAs. Heat stability and a partial trypsin digestion of the receptor both suggested that the action site of oleoyl‐CoA overlapped the T3‐binding domain of the receptor. In addition, thyroid hormone receptor β1, synthesized in vitro, bound oleoyl‐CoA specifically and its T3‐binding activity was inhibited. The dissociation constant for oleoyl‐CoA binding to the partially purified receptor was 1.2 × 10−7 M. This value as well as its molecular size distinguished the nuclear binding sites from the cytoplasmic fatty acid/acyl‐CoA binding proteins. Oleoyl‐CoA had no effect on the glucocorticoid receptor, another member of the nuclear hormone‐receptor superfamily. From these results, we propose that thyroid hormone receptor is a specific acyl‐CoA binding protein of the cell nucleus.
Differential expression of the chromosomal high mobility group proteins 14 and 17 during the onset of differentiation in mammalian osteoblasts and promyelocytic leukemia cells
Authors: Shakoori Abdul Rauf , Owen Thomas A. , Shalhoub Victoria , Stein Janet L. , Bustin Michael , Stein Gary S. , Lian Jane B.
Published: June 2014

The expression of chromosomal proteins HMG 14 and HMG 17 during proliferation and differentiation into the osteoblast and monocyte phenotypes was studied. Cellular levels of HMG 14 and HMG 1 7 mRNA were assayed in primary cultures of calvarial‐derived rat osteoblasts under conditions that (1) support complete expression of the mature osteocytic phenotype and development of a bone tissue‐like organization; and (2) where development of osteocytic phenotypic properties are both delayed and reduced in extent of expression. HMG 14 and HMG 17 are preferentially expressed in proliferating osteoblasts and decline to basal levels post‐proliferatively at the onset of extracellular matrix mineralization. In contrast, under conditions that are not conducive to extracellular matrix mineralization, HMG 14 is maximally expressed following the downregulation of proliferation. Consistent with previous reports by Bustin and co‐workers [Crippa et al., 1990], HMG 14 and HMG 17 are expressed in proliferating HL‐60 promyelocytic leukemia cells and downregulated post‐proliferatively following phorbol ester‐induced monocytic differentiation. However, differentiation into the monocyte phenotype is accompanied by reinitiation of HMG 17 gene expression. The results indicate that the levels of HMG 14 and HMG 17 mRNA are selectively down‐regulated during differentiation.
Entecavir plus adefovir combination therapy versus lamivudine add‐on adefovir for lamivudine‐resistant chronic hepatitis B: A meta‐analysis
Authors: Zeng Teng , Xu Hua , Liu Jun‐Ying , Lei Yu , Zhong Shan , Zhou Zhi
Published: June 2014

To determine whether adefovir (ADV) in combination with entecavir (ETV) is more effective than with lamivudine (LAM) in patients with lamivudine‐resistant chronic HBV infection, electronic databases were searched through May 10th, 2013 to obtain relevant trials which met the inclusion criteria. Meta‐analysis was performed on randomized controlled trials (RCTs) and non‐randomized studies. Four trials containing a total of 323 patients were included. Serum HBV DNA reductions after 3 and 6 months of treatment in the ETV + ADV group were greater than that of LAM + ADV group (mean difference (MD) = 0.90, 95% confidence interval (CI): 0.74–1.07, P < 0.00001; MD = 0.81, 95% CI: 0.57–1.06, P < 0.00001). The rate of 6 months HBV DNA undetectability with ETV and ADV was higher than that of LAM and ADV (relative risk (RR) = 1.63, 95% CI: 1.14–2.34, P < 0.007). There were higher rates of serum ALT normalization than those in LAM + ADV group after 6 months of treatment (RR = 1.40, 95% CI: 1.11–1.77, P < 0.005). The ETV + ADV group had lower viral breakthrough and genotypic mutation rates than LAM + ADV group after 12 months of treatment (RR = 0.24, 95% CI: 0.10–0.58, P = 0.002). The combination of ETV plus ADV is a more effective rescue therapy than LAM add‐on ADV in patients with LAM‐resistant HBV.
Mechanisms of impulsive choice: I. Individual differences in interval timing and reward processing
Authors: Marshall Andrew T. , Smith Aaron P. , Kirkpatrick Kimberly
Published: June 2014

Impulsive choice behavior incorporates the psychological mechanisms involved in the processing of the anticipated magnitude and delay until reward. The goal of the present experiment was to determine whether individual differences in such processes related to individual differences in impulsive choice behavior. Two groups of rats (Delay Group and Magnitude Group) were initially exposed to an impulsive choice task with choices between smaller–sooner (SS) and larger–later (LL) rewards. The Delay Group was subsequently exposed to a temporal discrimination task followed by a progressive interval task, whereas the Magnitude Group was exposed to a reward magnitude sensitivity task followed by a progressive ratio task. Intertask correlations revealed that the rats in the Delay Group that made more self‐controlled (LL) choices also displayed lower standard deviations in the temporal bisection task and greater delay tolerance in the progressive interval task. Impulsive choice behavior in the Magnitude Group did not display any substantial correlations with the reward magnitude sensitivity and progressive ratio tasks. The results indicate the importance of core timing processes in impulsive choice behavior, and encourage further research examining the effects of changes in core timing processes on impulsive choice.
Emergence of auditory–visual relations from a visual–visual baseline with auditory‐specific consequences in individuals with autism
Authors: Varella André A. B. , de Souza Deisy G.
Published: June 2014

Empirical studies have demonstrated that class‐specific contingencies may engender stimulus–reinforcer relations. In these studies, crossmodal relations emerged when crossmodal relations comprised the baseline, and intramodal relations emerged when intramodal relations were taught during baseline. This study investigated whether auditory–visual relations (crossmodal) would emerge after participants learned a visual–visual baseline (intramodal) with auditory stimuli presented as specific consequences. Four individuals with autism learned AB and CD relations with class‐specific reinforcers. When A1 and C1 were presented as samples, the selections of B1 and D1, respectively, were followed by an edible (R1) and a sound (S1). Selections of B2 and D2 under the control of A2 and C2, respectively, were followed by R2 and S2. Probe trials tested for visual–visual AC, CA, AD, DA, BC, CB, BD, and DB emergent relations and auditory–visual SA, SB, SC, and SD emergent relations. All of the participants demonstrated the emergence of all auditory–visual relations, and three of four participants showed emergence of all visual–visual relations. Thus, the emergence of auditory–visual relations from specific auditory consequences suggests that these relations do not depend on crossmodal baseline training. The procedure has great potential for applied technology to generate auditory–visual discriminations and stimulus classes in the context of behavior‐analytic interventions for autism.
On Hypohamiltonian and Almost Hypohamiltonian Graphs
Authors: Zamfirescu Carol T.
Published: June 2014

A graph G is almost hypohamiltonian if G is non‐hamiltonian, there exists a vertex w such that is non‐hamiltonian, and for any vertex the graph is hamiltonian. We prove the existence of an almost hypohamiltonian graph with 17 vertices and of a planar such graph with 39 vertices. Moreover, we find a 4‐connected almost hypohamiltonian graph, while Thomassen's question whether 4‐connected hypohamiltonian graphs exist remains open. We construct planar almost hypohamiltonian graphs of order n for every . During our investigation we draw connections between hypotraceable, hypohamiltonian, and almost hypohamiltonian graphs, and discuss a natural extension of almost hypohamiltonicity. Finally, we give a short argument disproving a conjecture of Chvátal (originally disproved by Thomassen), strengthen a result of Araya and Wiener on cubic planar hypohamiltonian graphs, and mention open problems.
Image reconstruction: An overview for clinicians
Authors: Hansen Michael S. , Kellman Peter
Published: June 2014

Image reconstruction plays a critical role in the clinical use of magnetic resonance imaging (MRI). The MRI raw data is not acquired in image space and the role of the image reconstruction process is to transform the acquired raw data into images that can be interpreted clinically. This process involves multiple signal processing steps that each have an impact on the image quality. This review explains the basic terminology used for describing and quantifying image quality in terms of signal‐to‐noise ratio and point spread function. In this context, several commonly used image reconstruction components are discussed. The image reconstruction components covered include noise prewhitening for phased array data acquisition, interpolation needed to reconstruct square pixels, raw data filtering for reducing Gibbs ringing artifacts, Fourier transforms connecting the raw data with image space, and phased array coil combination. The treatment of phased array coils includes a general explanation of parallel imaging as a coil combination technique. The review is aimed at readers with no signal processing experience and should enable them to understand what role basic image reconstruction steps play in the formation of clinical images and how the resulting image quality is described. J. Magn. Reson. Imaging 2014. © 2014 Wiley Periodicals, Inc. J. Magn. Reson. Imaging 2015;41:573–585. © 2014 Wiley Periodicals, Inc.
Delayed thalamic astrocytosis and disrupted sleep–wake patterns in a preclinical model of traumatic brain injury
Authors: Hazra Anupam , Macolino Christine , Elliott Melanie B. , Chin Jeannie
Published: June 2014

Traumatic brain injury (TBI) involves diffuse axonal injury and induces subtle but persistent changes in brain tissue and function and poses challenges for early detection of neurological injury. The present study uses an automated behavioral analysis system to assess alterations in rodent behavior in the subacute phase in a preclinical mouse model of TBI, controlled cortical impact (CCI) injury. In the first few weeks following CCI, mice demonstrated normal exploratory behaviors and other typical home‐cage behaviors. However, beginning 4 weeks post‐injury, CCI mice developed disruptions in sleep–wake patterns, including an increased number of awakenings from sleep. Such impaired sleep maintenance was accompanied by an increased latency to reach peak sleep in CCI mice. These sleep disruptions implicate involvement of the thalamocortical network, the activity of which must be tightly regulated to control sleep maintenance. After injury, there was an increase in reactive microglia in thalamic regions as well as delayed reactive astrocytosis that was evident in the thalamic reticular nucleus, which preceded the development of sleep disruptions. These data suggest that cortical injury may trigger inflammatory responses in deeper neuroanatomical structures, including the thalamic reticular nucleus. Such engagement of the thalamus may perturb the thalamocortical network that regulates sleep/awake patterns and contribute to sleep disruptions observed in this model as well as those documented in patients with TBI. © 2014 Wiley Periodicals, Inc.
Tumor necrosis factor‐α inhibitors alleviation of experimentally induced neuropathic pain is associated with modulation of TNF receptor expression
Authors: Andrade Pablo , Hoogland Govert , Del Rosario John S. , Steinbusch Harry W. , Visser‐Vandewalle Veerle , Daemen Marc A.
Published: June 2014

Inflammation plays a key role in the development of sensitization after peripheral nerve damage. We recently demonstrated that tumor necrosis factor‐α receptor (TNFR) levels in the spinal cord correlate with pain sensation in herniated disc patients in a rat chronic constriction injury (CCI) model. By using the sciatic nerve CCI model, we studied the effect of anti‐TNF‐α treatment on recovery from hypersensitivity and TNFR expression in the dorsal root ganglion (DRG) and dorsal horn (DH). Experimental groups consisted of sham‐operated and CCI‐operated rats that received two s.c. injections (one immediately after surgery, the other 5 days later), both containing saline, etanercept (3 mg/kg body weight), or infliximab (10 mg/kg body weight). Mechanical allodynia (with von Frey filaments) and thermal hyperalgesia (Hargreaves test) were assessed preoperatively and weekly during the first 4 postoperative weeks. DRG and DH samples were collected 2 and 4 weeks after surgery and analyzed for TNFR1 and TNFR2 protein levels by Western blotting and analyzed for mRNA levels by quantitative real‐time polymerase chain reaction. Anti‐TNF‐α treatment resulted in a significant alleviation of pain. TNFR levels were increased five‐ to sixfold in CCI rats compared with sham controls. Both treatments significantly diminished these increased levels. Treated animals that showed a ≥50% alleviation of pain exhibited a significantly reduced TNF R1/R2 mRNA ratio compared with treated animals that recovered less well. These results demonstrate that attenuation of TNFR expression is associated with recovery from nerve injury and suggest that this may be one of the working mechanisms of anti‐TNF therapies. © 2014 Wiley Periodicals, Inc.
Enhanced electrical responsiveness in the cerebral cortex with oral melatonin administration after a small hemorrhage near the internal capsule in rats
Authors: Ueda Yoshitomo , Masuda Tadashi , Ishida Akimasa , Misumi Sachiyo , Shimizu Yuko , Jung Cha‐Gyun , Hida Hideki
Published: June 2014

Intracerebral hemorrhage (ICH) can cause direct brain injury at the insult site and indirect damage in remote brain areas. Although a protective effect of melatonin (ML) has been reported for ICH, its detailed mechanisms and effects on remote brain injury remain unclear. To clarify the mechanism of indirect neuroprotection after ICH, we first investigated whether ML improved motor function after ICH and then examined the underlying mechanisms. The ICH model rat was made by collagenase injection into the left globus pallidus, adjacent to the internal capsule. ML oral administration (15 mg/kg) for 7 days after ICH resulted in significant recovery of motor function. Retrograde labeling of the corticospinal tract by Fluoro‐Gold revealed a significant increase in numbers of positive neurons in the cerebral cortex. Immunohistological analysis showed that ML treatment induced no difference in OX41‐positive activated microglia/macrophage at day 1 (D1) but a significant reduction in 8‐hydroxydeoxyguanosin‐positive cells at D7. Neutral red assay revealed that ML significantly prevented H2O2‐induced cell death in cultured oligodendrocytes and astrocytes but not in neurons. Electrophysiological response in the cerebral cortex area where the number of Fluoro‐Gold‐positive cells was increased was significantly improved in ML‐treated rats. These data suggest that ML improves motor abilities after ICH by protecting oligodendrocytes and astrocytes in the vicinity of the lesion in the corticospinal tract from oxidative stress and causes enhanced electrical responsiveness in the cerebral cortex remote to the ICH pathology. © 2014 Wiley Periodicals, Inc.
Seasonal variability of the main components in essential oil of Mentha × piperita L.
Authors: Grulova Daniela , De Martino Laura , Mancini Emilia , Salamon Ivan , De Feo Vincenzo
Published: June 2014

BACKGROUND

Mentha × piperita is an important and commonly used flavoring plant worldwide. Its constituents, primarily menthol and menthone, change in the essential oil depending on internal and external factors, of which environmental conditions appear very important. The experiment was established in 2010 for three vegetation season, in order to observe the quantitative changes of the main components of peppermint. The determination of menthol, menthone, limonene, menthyl acetate, menthofuran and β‐caryophyllene was registered.

RESULTS

In the experimental season 2011 and 2012 a higher mean temperature than in 2010 and extreme rainfall in July 2011 and 2012 were recorded. Different environmental conditions affected the development of M. × piperita plants and the content and composition of the essential oil.

CONCLUSION

Seasonal and maturity variations are interlinked with each other, because the specific ontogenic growth stage differed as the season progressed. Fluctuations in monthly and seasonal temperature and precipitation patterns affected the quality of peppermint essential oil. © 2014 Society of Chemical Industry
Outcomes in the management of adult soft tissue sarcomas
Authors: Kneisl Jeffrey S. , Coleman Michelle M. , Raut Chandrajit P.
Published: June 2014

Adult soft tissue sarcomas (STSs) are heterogeneous neoplasms that account for 11,410 new diagnoses and 4,390 deaths per year. This article summarizes recent NCCN guidelines for diagnosis and management of STSs of the extremities and retroperitoneum, as well as gastrointestinal stromal tumors (GIST). AJCC staging and recently reported NCDB data regarding outcomes are reviewed. Currently accepted STS prognostic variables are presented, as are future directions regarding the utility of molecular prognosticators and nomograms. J. Surg. Oncol. 2014 110:527–538. © 2014 Wiley Periodicals, Inc.
Nonalcoholic fatty liver disease after pancreatoduodenectomy is closely associated with postoperative pancreatic exocrine insufficiency
Authors: Nakagawa Naoya , Murakami Yoshiaki , Uemura Kenichiro , Sudo Takeshi , Hashimoto Yasushi , Kondo Naru , Sasaki Hayato , Okano Keisuke , Sueda Taijiro
Published: June 2014

Background

In recent years, nonalcoholic fatty liver disease (NAFLD) after pancreatoduodenectomy (PD) has become increasingly problematic. Our aims were to clarify the relationship between NAFLD and postoperative pancreatic exocrine function and to identify the risk factors for NAFLD after PD.

Methods

Patients who underwent PD (n = 104) were assessed with abdominal unenhanced computed tomography (CT) to determine the fatty liver changes and were given a 13C‐labeled mixed triglyceride breath test to measure pancreatic exocrine function. The percent 13CO2 cumulative dose at 7 hr (% dose 13C cum 7 hr) <5% was considered diagnostic for pancreatic exocrine insufficiency (PEI). Relationships between the occurrence of NAFLD and clinical factors including postoperative pancreatic exocrine function were analyzed.

Results

Twenty‐six of 104 patients (25%) developed postoperative NAFLD. The postoperative CT attenuation of the liver (R = 0.326, P < 0.001) and the liver‐to‐spleen attenuation ratio (R = 0.315, P = 0.001) significantly correlated with the postoperative values of % dose 13C cum 7 hr. Multivariate analysis determined that postoperative PEI was the only independent risk factor for NAFLD (P = 0.025).

Conclusions

NAFLD frequently occurs postoperatively after PD. NAFLD after PD may be closely associated with postoperative PEI. J. Surg. Oncol. 2014 110:720–726. © 2014 Wiley Periodicals, Inc.
Prophylactic mastectomy: Who needs it, when and why
Authors: Burke Erin E. , Portschy Pamela R. , Tuttle Todd M.
Published: June 2014

Prophylactic mastectomy generally occurs in two different patient populations: (1) high‐risk women without breast cancer who undergo bilateral prophylactic mastectomy (BPM) to reduce their risk of developing breast cancer and (2) women with unilateral breast cancer who choose contralateral prophylactic mastectomy (CPM) to prevent cancer in the contralateral breast. The purpose of this article is to review the indications, outcomes, and trends in the use of BPM and CPM. J. Surg. Oncol. 2015 111:91–95. © 2014 Wiley Periodicals, Inc.
Prophylactic thyroidectomy: Who needs it, when, and why
Authors: Wang Tracy S. , Opoku‐Boateng Adwoa , Roman Sanziana A. , Sosa Julie Ann
Published: June 2014

The most common hereditary thyroid cancer is medullary thyroid cancer, which can be associated with MEN 2A, MEN 2B, or FMTC. In these patients, prophylactic thyroidectomy is recommended; timing of surgery is dependent on the specific RET mutation. Prophylactic thyroidectomy should include total thyroidectomy and accompanying central compartment neck dissection should be done for patients at high risk for micro‐metastatic disease only. Surgery should be performed at tertiary care institutions by high‐volume thyroid surgeons. J. Surg. Oncol. 2015 111:61–65. © 2014 Wiley Periodicals, Inc.
Investigating effects of sample pretreatment on protein stability using size‐exclusion chromatography and high‐resolution continuum source atomic absorption spectrometry
Authors: Rakow Tobias , El Deeb Sami , Hahne Thomas , El‐Hady Deia Abd , AlBishri Hassan M. , Wätzig Hermann
Published: June 2014

In this study, size‐exclusion chromatography and high‐resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short‐term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high‐resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high‐performance size‐exclusion chromatography, adsorption caused sample losses of up to 33%.
Development of a Joule‐class Yb:YAG amplifier and its implementation in a CPA system generating 1 TW pulses
Authors: Wandt Christoph , Klingebiel Sandro , Keppler Sebastian , Hornung Marco , Loeser Markus , Siebold Mathias , Skrobol Christoph , Kessel Alexander , Trushin Sergei A. , Major Zsuzsanna , Hein Joachim , Kaluza Malte C. , Krausz Ferenc , Karsch Stefan
Published: June 2014

In this paper the development and implementation of a novel amplifier setup as an additional stage for the CPA pump laser of the Petawatt Field Synthesizer, currently developed at the Max‐Planck‐Institute of Quantum Optics, is presented. This amplifier design comprises 20 relay‐imaged passes through the active medium which are arranged in rotational symmetry. As the gain material, an in‐house‐developed Yb:YAG active‐mirror is used. With this setup, stretched 4 ns seed pulses are amplified to output energies exceeding 1 J with repetition rates of up to 2 Hz. Furthermore, a spectral bandwidth of 3.5 nm (FWHM) is maintained during amplification and the compression of the pulses down to their Fourier‐limit of 740 fs is achieved. To the best of our knowledge, this is the first demonstration of 1 TW pulses generated via CPA in diode‐pumped Yb:YAG.
Laparoscopy-Assisted Hepatectomy Versus Conventional (Open) Hepatectomy for Living Donors: When You Know Better, You Do Better
Authors: Makki Kausar , Chorasiya Vishal Kumar , Sood Gaurav , Srivastava Piyush Kumar , Dargan Puneet , Vij Vivek
Published: June 2014

The conventional incision for donor hepatectomy is a right subcostal incision with a midline extension. With increased experience in both donor hepatectomy and laparoscopy, the conventional incision can be shortened to a significant extent. Laparoscopic mobilization of the liver coupled with a hand port allows the insertion of one hand inside the abdomen for control; this makes small-incision donor hepatectomy a technically feasible alternative. We compared 26 right lobe donor hepatectomies performed with a laparoscopy-assisted technique (the laparoscopy-assisted donor hepatectomy group) to 24 donor hepatectomies performed with the conventional open technique (the conventional donor hepatectomy group). The donors in both groups and their recipients were followed for 6 months. Pain, discomfort related to the scar [including abdominal wall sensorineural deficits (numbness and differences in tactile and temperature sensations) and tightness around the scar], and donor quality of life (assessed with the International Quality of Life Assessment Short Form 8 scoring system) were compared between the 2 groups. In conclusion, laparoscopy-assisted surgery can be a technically feasible alternative in experienced hands, and as with other minimally invasive surgeries, it has advantages such as significantly less pain, reduced incision-related complications, and better donor quality of life during the early postoperative period without compromising donor safety. Liver Transpl 20:1229–1236, 2014. © 2014 AASLD.
A New Generation of Furanic Copolyesters with Enhanced Degradability: Poly(ethylene 2,5‐furandicarboxylate)‐co‐poly(lactic acid) Copolyesters
Authors: Matos Marina , Sousa Andreia F. , Fonseca Ana C. , Freire Carmen S. R. , Coelho Jorge F. J. , Silvestre Armando J. D.
Published: June 2014

2,5‐Furandicarboxylic acid is a promising renewable‐based monomer essentially used in polymer synthesis to prepare renewable‐based counterparts to petrochemical polyesters. In general, they are entirely based on renewable resources and have a myriad of very interesting thermal and mechanical properties; however, this study is the first to tackle their (bio)degradability, a worldwide‐demanded property. To address this demand, an entirely new generation of furandicarboxylate‐derived copolyesters, based on both poly(ethylene 2,5‐furandicarboxylate) (PEF) and poly(lactic acid) (PLA), is developed for the first time. These copolyesters are characterized by several techniques, including attenuated total reflectance‐Fourier transform IR (ATR‐FTIR), 1H, and 13C NMR spectroscopy, thermogravimetric analysis (TGA), DSC, and X‐ray diffraction (XRD), and their degradability behavior is evaluated by water‐absorption studies and hydrolytic degradation. They are essentially stiff amorphous polymers possessing high Tgs, e.g., ca. 69 °C for 29% of lactyl units. Importantly, the data show also that they have improved degradability when compared with the PEF homopolyester counterpart.

image
Clickable Poly(ethylene glycol)‐Based Copolymers Using Azide–Alkyne Click Cycloaddition‐Mediated Step‐Growth Polymerization
Authors: Arslan Mehmet , Gok Ozgul , Sanyal Rana , Sanyal Amitav
Published: June 2014

The design, synthesis, and post‐polymerization functionalization of linear poly(ethylene glycol) (PEG)‐based polytriazole copolymers containing thiol‐reactive maleimide functional groups as pendant side chains are described. A copper(I)‐catalyzed Huisgen‐type 1,3‐dipolar cycloaddition reaction is utilized to prepare copolymers through a combination of diazide‐ and dialkyne‐functionalized triethylene glycol derivatives, along with a dialkyne‐functionalized furan‐protected maleimide‐containing monomer. After the polymerization, a microwave‐assisted retro‐Diels–Alder reaction is utilized to unmask the pendant maleimide groups by removal of the furan moieties. Post‐polymerization modifications of these PEG‐based copolymers containing the furan‐protected maleimide group are accomplished using a photoinitiated radical thiol‐ene reaction, whereas polymers containing the reactive maleimide group are functionalized using the Diels–Alder and nucleophilic thiol‐ene reactions. The nucleophilic thiol‐ene reaction is utilized to fabricate hydrogels by treatment of the maleimide‐containing PEG polymers with dithiol‐containing crosslinkers. Facile functionalization of thus‐obtained hydrogels under mild conditions is demonstrated through the treatment of the residual maleimide groups within the hydrogel with a thiol‐containing fluorescent dye.

image
Topologies for intermediate logics
Authors: Caramello Olivia
Published: June 2014

We investigate the problem of characterizing the classes of Grothendieck toposes whose internal logic satisfies a given assertion in the theory of Heyting algebras, and introduce natural analogues of the double negation and De Morgan topologies on an elementary topos for a wide class of intermediate logics.
Development of Glassy Step‐Growth Thiol‐Vinyl Sulfone Polymer Networks
Authors: Podgórski Maciej , Chatani Shunsuke , Bowman Christopher N.
Published: June 2014

Thermomechanical properties of neat phosphine‐catalyzed thiol‐Michael networks fabricated in a controlled manner are reported, and a comparison between thiol‐acrylate and thiol‐vinyl sulfone step‐growth networks is performed. When highly reactive vinyl sulfone monomers are used as Michael acceptors, glassy polymer networks are obtained with glass transition temperatures ranging from 30 to 80 °C. Also, the effect of side‐chain functionality on the mechanical properties of thiol‐vinyl sulfone networks is investigated. It is found that the inclusion of thiourethane functionalities, aryl structures, and most importantly the elimination of interchain ester linkages in the networks significantly elevate the network's glass transition temperature as compared with neat ester‐based thiol‐Michael networks.

image
Synthesis, Characterization, and Combustion Catalytic Activities of Copper(II) and Lead(II) Salts of p‐Nitrocalix[n]arenes (n=4, 6, 8)
Authors: Zhang Guofang , Wang Chunyan , An Ting , Zhao Fengqi , Fan Xuezhong
Published: June 2014

Six copper(II) and lead(II) salts of p‐nitrocalix[n]arene (n=4, 6, 8) were synthsized and characterized. The DSC curves of all salts showed exothermic decomposition. Sensitivity studies revealed that all the salts with the exception of the lead salt of p‐nitrocalix[6]arene (NCPb6) are relatively insensitive materials. Investigations of the catalytic activities showed that most of the salts displayed high activities in thermal decomposition of NC‐NG and RDX. As evaluated in this work, the salts enhanced the burning rates of both double base (DB) and RDX‐component modified double base propellants. The best catalytic effect was obtained with NCPb6, which increased the burning rate of the DB propellant to the order of about 200 % (2–6 MPa) and 103–198 % (8–20 MPa) while decreasing the pressure index (n) to 0.22 (20–22 MPa).
Biofumigation with Brassica juncea, Raphanus sativus and Eruca sativa for the management of field populations of the potato cyst nematode Globodera pallida
Authors: Ngala Bruno M , Haydock Patrick PJ , Woods Simon , Back Matthew A
Published: June 2014

BACKGROUND

The viability of potato cyst nematode (PCN) populations (Globodera pallida) was evaluated in three field experiments using Brassica juncea, Raphanus sativus and Eruca sativa amendments. These species were summer cultivated and autumn incorporated in experiment 1; in experiment 2, overwintered brassicaceous cover crops were spring incorporated. Experiment 3 involved determination of effects of metconazole application on biomass/glucosinolate production by B. juncea and R. sativus and on PCN pre‐ and post‐incorporation. Glucosinolate contents were determined before incorporation. Following cover crop incorporation, field plots were planted with susceptible potatoes to evaluate the biofumigation effects on PCN reproduction.

RESULTS

In experiment 1, PCN population post‐potato harvest was reduced (P = 0.03) in B. juncea‐treated plots, while R. sativus prevented further multiplication, but in experiment 2 there were no significant effects on PCN reproduction. In experiment 3, B. juncea or R. sativus either untreated or treated with metconazole reduced PCN populations. Glucosinolate concentrations varied significantly between different plant regions and cultivation seasons. Metconazole application increased the sinigrin concentration in B. juncea tissues. Glucosinolate concentrations correlated positively with PCN mortality for summer‐cultivated brassicaceous plants.

CONCLUSION

The results demonstrated that B. juncea and R. sativus green manures can play an important role in PCN management, particularly if included in an integrated pest management scheme. © 2014 Society of Chemical Industry
Reliability Reallocation for Fuel Cell Vehicles Based on Genetic Algorithm
Authors: Liu Xintian , Zheng Songlin , Feng Jinzhi , Chen Tie
Published: June 2014

A fuel cell vehicle (FCV) is a type of alternative energy vehicle that could help resolve the energy crisis, mitigate environmental problems, and contribute to sustainable development. Developing an FCV with high reliability is an important goal for automobile factories and research institutions. Other key factors required by FCVs include mass production and customer approval. An FCV is a complex mechanism composed of many subsystems. During the development of the overall vehicle, steps should be taken to ensure that every subsystem is reliable. However, such development must also consider costs, which must be kept as low as possible. To ensure the reliability of FCV while operating under conditions that demand minimal cost, a genetic algorithm is employed to reallocate the reliability of the overall vehicle system. First, the growth factor of the reliability–feasibility of each subsystem is determined according to the complexity, importance, and technological level of the FCV subsystems. The FCV cost model is then established on the basis of such parameters as subsystem cost, reliability–feasibility growth factor, initial reliability, limit reliability, and so on. A genetic algorithm is then used to compute for the reliability of FCV subsystems. The rationality of reliability reallocation is verified according to the subsystem importance coefficient. This method considers the benefits for both enterprises and customers by applying principles of engineering and conducting a reliability study. Copyright © 2014 John Wiley & Sons, Ltd.
Dimer ion formation and intermolecular fragmentation of 1,2‐diacylglycerols revealed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry for more comprehensive lipid analysis
Authors: Müller Constanze , Kanawati Basem , Rock Theresa M. , Forcisi Sara , Moritz Franco , Schmitt‐Kopplin Philippe
Published: June 2014

RATIONALE

The ionization of neutral diacylglycerols (DAGs) by electrospray ionization mass spectrometry (ESI‐MS) is challenging compared with other lipid classes which possess ionic head group conjugations. Although ESI‐MS is the method of choice in lipidomic analysis, it is questionable whether all lipid classes can be efficiently ionized by this method. Actually, various lipids were not efficiently detected (due to poor ionization) in many studies which claimed to comprehensively describe lipid profiles. Since neutral lipids are precursors for the biosynthesis of most other lipid classes, the necessity for improved or alternative ionization and identification schemes becomes obvious.

METHODS

We identified the 1,2‐diacylglycerol (DAG) dimer ion formation in the gas phase by ultra‐high‐resolution Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR‐MS) in negative electrospray ionization ((−)ESI) mode. The geometry of the dimer ion was investigated by accurate density functional theory (DFT) calculations at the B3LYP/6‐311+G(d)//B3LYP/LANL2DZ level of theory. Fragmentation of the dimer ions of many investigated DAGs has been achieved via collision‐induced dissociation (CID) experiments with several elevated collision energies (0–12 eV).

RESULTS

We revealed the possibility to ionize neutral DAGs as dimer ions in the negative ESI mode. Quantum mechanical calculations revealed a polar head‐to‐head intermolecular interaction between one charged DAG and one DAG neutral. This represents an energy minimum structure for the DAG dimer ions. We could furthermore detect CID fragmentation product ions that can only result from intermolecular reactions in this head‐to‐head conformation (SN2 nucleophilic substitution reactions inside the dimer DAG ion).

CONCLUSIONS

Here, we present for the first time the opportunity to ionize and identify DAGs as dimer ions. This new finding provides a new alternative for investigations of important diacylglycerol lipids and provides the opportunity to obtain complementary and more comprehensive results in future lipidomic studies. Copyright © 2014 John Wiley & Sons, Ltd.
Utilizing the firm's resources: How TMT heterogeneity and resulting faultlines affect TMT tasks
Authors: Ndofor Hermann Achidi , Sirmon David G. , He Xiaoming
Published: June 2014

While theory and evidence show that firms' competitive actions mediate the resource‐performance relationship, details of top managements' roles in shaping resource utilization choices have been underemphasized. We address this oversight by integrating top management team heterogeneity and any resulting faultline strength with the resource‐action‐performance model to investigate how TMT composition differentially affects the model's two linkages. Specifically, we argue that TMT heterogeneity positively affects the resource‐action linkage, yet negatively affects the action‐performance linkage. Moreover, when heterogeneity begets strong faultlines, all such positive effect is lost. Supportive evidence from the in‐vitro medical diagnostic substance manufacturing industry allows us to discuss how our findings contribute to upper echelons theory, as well as the emerging stream on resource utilization. Copyright © 2014 John Wiley & Sons, Ltd.
HucMSC-Exosome Mediated-Wnt4 Signaling Is Required for Cutaneous Wound Healing
Authors: Zhang Bin , Wang Mei , Gong Aihua , Zhang Xu , Wu Xiaodan , Zhu Yanhua , Shi Hui , Wu Lijun , Zhu Wei , Qian Hui , Xu Wenrong
Published: June 2014

Mesenchymal stem cell-derived exosomes (MSC-Ex) play important roles in tissue injury repair, however, the roles of MSC-Ex in skin damage repair and its mechanisms are largely unknown. Herein, we examined the benefit of human umbilical cord MSC-derived exosome (hucMSC-Ex) in cutaneous wound healing using a rat skin burn model. We found that hucMSC-Ex-treated wounds exhibited significantly accelerated re-epithelialization, with increased expression of CK19, PCNA, collagen I (compared to collagen III) in vivo. HucMSC-Ex promoted proliferation and inhibited apoptosis of skin cells after heat-stress in vitro. We also discovered that Wnt4 was contained in hucMSC-Ex, and hucMSC-Ex-derived Wnt4 promoted β-catenin nuclear translocation and activity to enhance proliferation and migration of skin cells, which could be reversed by β-catenin inhibitor ICG001. In vivo studies confirmed that the activation of Wnt/β-catenin by hucMSC-Ex played a key role in wound re-epithelialization and cell proliferation. Furthermore, knockdown of Wnt4 in hucMSC-Ex abrogated β-catenin activation and skin cell proliferation and migration in vitro. The in vivo therapeutic effects were also inhibited when the expression of Wnt4 in hucMSC-Ex was interfered. In addition, the activation of AKT pathway by hucMSC-Ex was associated with the reduction of heat stress-induced apoptosis in rat skin burn model. Collectively, our findings indicate that exosome-delivered Wnt4 provides new aspects for the therapeutic strategy of MSCs in cutaneous wound healing. Stem Cells 2015;33:2158–2168
Morphine Modulates Mouse Hippocampal Progenitor Cell Lineages by Upregulating miR-181a Level
Authors: Xu Chi , Zhang Yue , Zheng Hui , Loh Horace H. , Law Ping-Yee
Published: June 2014

The mechanism by which addictive drugs such as morphine regulate adult neurogenesis remains elusive. We now demonstrate that morphine can regulate neurogenesis by control of miR-181a and subsequent hippocampal neural progenitor cell (hNPC) lineages. In the presence of morphine, hNPCs preferentially differentiated into astrocytes, an effect blocked by the specific μ-opioid receptor antagonist, Cys2-Tyr3-Orn5-Pen7-amide. This effect was mediated by the Prox1/Notch1 pathway as demonstrated by an increase in Notch1 level in the morphine- but not fentanyl-treated hNPCs and blocked by overexpression of Notch1 siRNA. Overexpression of Prox1 siRNA upregulated Notch1 level and potentiated the morphine-induced lineage changes. Prox1 transcript level was regulated by direct interaction between miR-181a and its 3′-UTR sequence. In vitro and in vivo treatment with morphine resulted in an increase in miR-181a level in hNPCs and mouse hippocampi, respectively. Overexpression of miR-181a mimics reduced Prox1 levels, increased Notch1 levels, and enhanced hNPCs differentiation into astrocytes. Meanwhile, overexpression of the miR-181a inhibitor raised Prox1 levels, decreased Notch1 levels, and subsequently blocked the morphine-induced lineage changes. Thus, by modulating Prox1/Notch1 activities via miR-181a, morphine influences the fate of differentiating hNPCs differentiation and therefore the ultimate quantities of mature neurons and astrocytes. Stem Cells  2014;32:2961–2972
Brief Report: Serpin Spi2A as a Novel Modulator of Hematopoietic Progenitor Cell Formation
Authors: Li Lei , Byrne Susan M. , Rainville Nicole , Su Su , Jachimowicz Edward , Aucher Anne , Davis Daniel M. , Ashton-Rickardt Philip G. , Wojchowski Don M.
Published: June 2014

Prime regulation over hematopoietic progenitor cell (HPC) production is exerted by hematopoietins (HPs) and their Janus kinase-coupled receptors (HP-Rs). For HP/HP-R studies, one central challenge in determining specific effects involves the delineation of nonredundant signal transduction factors and their lineage restricted actions. Via loss-of-function studies, we define roles for an HP-regulated Serpina3g/Spi2A intracellular serpin during granulomyelocytic, B-cell, and hematopoietic stem cell (HSC) formation. In granulomyelocytic progenitors, granulocyte macrophage colony stimulating factor (GMCSF) strongly induced Serpina3g expression with Stat5 dependency. Spi2A-knockout (KO) led to 20-fold decreased CFU-GM formation, limited GMCSF-dependent granulocyte formation, and compromised neutrophil survival upon tumor necrosis factor alpha (TNF-α) exposure. In B-cell progenitors, Serpina3g was an interleukin-7 (IL7) target. Spi2A-KO elevated CFU-preB greater than sixfold and altered B-cell formation in competitive bone marrow transplant (BMT), and CpG challenge experiments. In HSCs, Serpina3g/Spi2A expression was also elevated. Spi2A-KO compromised LT-HSC proliferation (as well as lineageneg Sca1pos Kitpos (LSK) cell lysosomal integrity), and skewed LSK recovery post 5-FU. Spi2A therefore functions to modulate HP-regulated immune cell and HSC formation post-5-FU challenge. Stem Cells  2014;32:2550–2556