bluuebunny/crossref_metadata_2025 huggingface dataset:
Glial alterations from early to late stages in a model of Alzheimer's disease: Evidence of autophagy involvement in Aβ internalization
Authors: Pomilio Carlos , Pavia Patricio , Gorojod Roxana Mayra , Vinuesa Angeles , Alaimo Agustina , Galvan Veronica , Kotler Monica Lidia , Beauquis Juan , Saravia Flavia
Published: August 2015

Alzheimer's disease (AD) is a progressive neurodegenerative disease without effective therapy. Brain amyloid deposits are classical histopathological hallmarks that generate an inflammatory reaction affecting neuronal and glial function. The identification of early cell responses and of brain areas involved could help to design new successful treatments. Hence, we studied early alterations of hippocampal glia and their progression during the neuropathology in PDAPP‐J20 transgenic mice, AD model, at 3, 9, and 15 months (m) of age. At 3 m, before deposits formation, microglial Iba1+ cells from transgenic mice already exhibited signs of activation and larger soma size in the hilus, alterations appearing later on stratum radiatum. Iba1 immunohistochemistry revealed increased cell density and immunoreactive area in PDAPP mice from 9 m onward selectively in the hilus, in coincidence with prominent amyloid Congo red + deposition. At pre‐plaque stages, GFAP+ astroglia showed density alterations while, at an advanced age, the presence of deposits was associated with important glial volume changes and apparently being intimately involved in amyloid degradation. Astrocytes around plaques were strongly labeled for LC3 until 15 m in Tg mice, suggestive of increased autophagic flux. Moreover, β‐Amyloid fibrils internalization by astrocytes in in vitro conditions was dependent on autophagy. Co‐localization of Iba1 with ubiquitin or p62 was exclusively found in microglia contacting deposits from 9 m onward, suggesting torpid autophagy. Our work characterizes glial changes at early stages of the disease in PDAPP‐J20 mice, focusing on the hilus as an especially susceptible hippocampal subfield, and provides evidence that glial autophagy could play a role in amyloid processing at advanced stages. © 2015 Wiley Periodicals, Inc.
Mesenchymal stem cells regulate melanoma cancer cells extravasation to bone and liver at their perivascular niche
Authors: Correa Diego , Somoza Rodrigo A. , Lin Paul , Schiemann William P. , Caplan Arnold I.
Published: August 2015

Skeleton and liver are preferred organs for cancer dissemination in metastatic melanoma negatively impacting quality of life, therapeutic success and overall survival rates. At the target organ, the local microenvironment and cell‐to‐cell interactions between invading and resident stromal cells constitute critical components during the establishment and progression of metastasis. Mesenchymal stem cells (MSCs) possess, in addition to their cell progenitor function, a secretory capacity based on cooperativity with other cell types in injury sites including primary tumors (PT). However, their role at the target organ microenvironment during cancer dissemination is not known. We report that local MSCs, acting as pericytes, regulate the extravasation of melanoma cancer cells (MCC) specifically to murine bone marrow (BM) and liver. Intra‐arterially injected wild‐type MCC fail to invade those selective organs in a genetic model of perturbed pericyte coverage of the vasculature (PDGF‐Bret/ret), similar to CD146‐deficient MCC injected into wild type mice. Invading MCC interact with resident MSCs/pericytes at the perivascular space through co‐expressed CD146 and Sdf‐1/CXCL12‐CXCR4 signaling. Implanted engineered bone structures with MSCs/pericytes deficient of either Sdf‐1/CXCL12 or CD146 become resistant to invasion by circulating MCC. Collectively, the presence of MSCs/pericytes surrounding the target organ vasculature is required for efficient melanoma metastasis to BM and liver.
Contribution of Lumbar Spine BMD to Fracture Risk in Individuals With T-Score Discordance
Authors: Alarkawi Dunia , Bliuc Dana , Nguyen Tuan V , Eisman John A , Center Jacqueline R
Published: August 2015

Fracture risk estimates are usually based on femoral neck (FN) BMD. It is unclear how to address T-score discordance, where lumbar spine (LS) T-score is lower than FN T-score. The objective of this work was to examine the impact of LS BMD on fracture risk, in individuals with lower LS T-score than FN T-score. Participants aged 60+ years from the Dubbo Osteoporosis Epidemiology Study with LS and FN BMD measured at first visit, and were followed from 1989 to 2014. Five-hundred and seventy-three (573) of 2270 women and 131 of 1373 men had lower LS than FN T-score by ≥0.6 standard deviation (SD) (low-LS group based on least significant change). In low-LS women, each 1 SD lower LS T-score than FN was associated with a 30% increase in fracture risk (hazard ratio [HR] 1.30; 95% CI, 1.11 to 1.45). For low-LS men there was a 20% nonsignificant increase in fracture risk for each 1 SD lower LS than FN T-score (HR 1.20; 95% CI, 0.10 to 1.67). Low-LS women had greater absolute fracture risks than the rest of the women. This increased risk was more apparent for lower levels of FN T-score and in older age groups. At an FN T-score of –2, low-LS women had a 3%, 10%, and 23% higher 5-year absolute fracture risk than non-low LS women in the 60 to 69 year, 70 to 79 year, and 80+ years age-groups, respectively. Furthermore, an osteoporotic LS T-score increased 5-year absolute fracture risk for women with normal or osteopenic FN T-score by 10% to 13%. Men in the low-LS group had very few fractures; therefore, a meaningful analyses of fracture risk could not be conducted. This study shows the significant contribution of lower LS BMD to fracture risk over and above FN BMD in women. A LS BMD lower than FN BMD should be incorporated into fracture risk calculators at least for women in older age-groups. © 2015 American Society for Bone and Mineral Research.
Impact of cytochrome P450 2C19 polymorphisms on the pharmacokinetics of tacrolimus when coadministered with voriconazole
Authors: Imamura Chiyo K. , Furihata Kenichi , Okamoto Shinichiro , Tanigawara Yusuke
Published: August 2015

This study evaluated the effects of cytochrome P450 (CYP) 2C19 polymorphisms on tacrolimus pharmacokinetics when coadministered with voriconazole. Eighteen healthy volunteers, including 6 individuals in each CYP2C19 genotype (extensive metabolizers [EMs], intermediate metabolizers [IMs], and poor metabolizers [PMs]), received a single oral dose of 3 mg tacrolimus alone or in combination with 200 mg voriconazole twice daily at steady state. When tacrolimus was coadministered with voriconazole, a significant increase in area under its concentration‐time curve (AUC0‐24) was observed for all genotypes. AUC0‐12 of voriconazole in IMs and PMs were significantly higher than that in EMs (P < .05 and P < .01, respectively). Consequently, AUC0‐24 of tacrolimus in combination with voriconazole in IMs and PMs were also significantly higher than that in EMs (P < .05). These results demonstrate that CYP2C19 genotypes influenced the exposure of tacrolimus when coadministered with voriconazole, although tacrolimus is mainly metabolized by CYP3A.
Stress and strain distribution in demineralized enamel: A micro‐CT based finite element study
Authors: Neves Aline Almeida , Coutinho Eduardo , Alves Haimon Diniz Lopes , de Assis Joaquim Teixeira
Published: August 2015

Physiological oral mechanical forces may play a role on the progression of enamel carious lesions to cavitation. Thus, the aim of this study was to describe, by 3D finite element analysis, stress, and strain patterns in sound and carious enamel after a simulated occlusal load. Micro‐CT based models were created and meshed with tetrahedral elements (based on an extracted third molar), namely: a sound (ST) and a carious tooth (CT). For the CT, enamel material properties were assigned according to the micro‐CT gray values. Below the threshold corresponding to the enamel lesion (2.5 g/cm3) lower and isotropic elastic modulus was assigned (E = 18 GPa against E1 = 80 GPa, E2 = E3 = 20 GPa for sound enamel). Both models were imported into a FE solver where boundary conditions were assigned and a pressure load (500 MPa) was applied at the occlusal surface. A linear static analysis was performed, considering anisotropy in sound enamel. ST showed a more efficient transfer of maximum principal stress from enamel to the dentin layer, while for the CT, enamel layer was subjected to higher and concentrated loads. Maximum principal strain distributions were seen at the carious enamel surface, especially at the central fossa, correlating to the enamel cavity seen at the original micro‐CT model. It is possible to conclude that demineralized enamel compromises appropriate stress transfer from enamel to dentin, contributing to the odds of fracture and cavitation. Enamel fracture over a dentin lesion may happen as one of the normal pathways to caries progression and may act as a confounding factor during clinical diagnostic decisions. Microsc. Res. Tech. 78:865–872, 2015. © 2015 Wiley Periodicals, Inc.
Computerized histomorphometric study of the splenic collagen polymorphism: A control‐tissue for polarization microscopy
Authors: Alves Antoine , Gritsch Kerstin , Sirieix Camille , Drevon‐Gaillot Elodie , Bayon Yves , Clermont Gaëlle , Boutrand Jean‐Pierre , Grosgogeat Brigitte
Published: August 2015

Previous articles have pointed out the presence of type III collagen within the extracellular structure of the parenchymatous organs. This study aimed to quantitatively characterize the collagen polymorphism at the capsule and parenchymal trabeculae of the largest lymphoid organ of the body i.e., the spleen, in mouse, rat, and rabbit models. Following a Picrosirius Red‐Polarization procedure and computer assisted image analysis of paraffin sections, the results showed (1) a predominant and significantly higher amount of type III collagen in the trabeculae area compared to the capsule area in the three species, (2) no statistical difference among the three species concerning the parenchymal collagen polymorphism or the type I/type III collagen ratio, (3) a heterogeneous type I/type III collagen ratio varying from 0.86 (mouse) to 6.62 (rabbit) in the fibromuscular capsule region. A qualitative analysis corroborated these histomorphometric results. In conclusion, the spleen may be used as (1) a control tissue to qualitatively visualize type I and III collagen under polarization microscopy and to validate the quality of PSR staining (2) an aid to accurately calibrate the angle of polarization before quantitative measurements of type I and type III collagen. Among the studied species, the rabbit spleen appeared to be the most appropriate control tissue as it showed the highest amount of type I collagen in the capsule and a similarly high amount of type III collagen in the parenchymal trabeculae. Microsc. Res. Tech. 78:900–907, 2015. © 2015 Wiley Periodicals, Inc.
Detection of human bocavirus in nasopharyngeal aspirates versus in broncho‐alveolar lavage fluids in children with lower respiratory tract infections
Authors: Li Ling , Zhu Tian , Chen Zheng‐Rong , Yan Yong‐Dong , He Li‐Ping , Xu Hong‐Mei , Shao Xue‐Jun , Yin Fang , Ji Wei
Published: August 2015

To compare the presence of human bocavirus (HBoV) in nasopharyngeal aspirates (NPA) versus broncho‐alveolar lavage fluids (BAL) in children with lower respiratory tract infections (LRTIs), as revealed by real‐time PCR, in order to confirm the diagnostic validity of NPA samples. A retrospective 5‐year study was performed from 2009 to 2014 in 1,194 patients under the age of 17 years (mean age of 3 years) that were diagnosed with LRTIs and from whom both NPA and BAL were obtained. Clinical and demographic data were recorded, and NPA and BAL samples were analyzed for HBoV‐positivity by real‐time PCR. Of the 1,194 patients enrolled, 65 (5.4%) patients had HBoV detected from NPA, and 61 (5.1%) had HBoV detected from BAL. For HBoV, there was a significant association between the NPA and BAL samples (P < 0.001), but the diagnostic validity was relatively low (kappa = 0.414). When real‐time PCR‐positivity for HBoV in BAL was used as a reference for diagnosis, NPA had a good specificity and better positive predictive validity in male patients or those younger than 3 years of age. NPA has a similar yield and a good specificity for diagnosis of LRTIs with HBoV compared to BAL. The best diagnostic validity for NPA was detected in male patients or those younger than 3 years old. J. Med. Virol. 88:211–215, 2016. © 2015 Wiley Periodicals, Inc.
HHV‐6 encephalitis may complicate the early phase after allogeneic hematopoietic stem cell transplantation: Detection by qualitative multiplex PCR and subsequent quantitative real‐time PCR
Authors: Inazawa Natsuko , Hori Tsukasa , Yamamoto Masaki , Hatakeyama Naoki , Yoto Yuko , Nojima Masanori , Yasui Hiroshi , Suzuki Nobuhiro , Shimizu Norio , Tsutsumi Hiroyuki
Published: August 2015

Viral reactivation following hematopoietic stem cell transplantation (HSCT) can cause various complications especially viral encephalitis. In this prospective study, we investigated the correlation of post‐HSCT viral reactivation in blood with CNS dysfunction. We employed a multiplex PCR that detects 13 kinds of viruses as a first‐line screening test and real‐time PCR for subsequent quantitative evaluation. Five hundred ninety‐one whole blood samples were collected from 105 patients from before until 42 days after HSCT. Seven patients developed CNS dysfunction such as altered consciousness. In six of the seven, the multiplex PCR test detected HHV‐6 DNA in at least one sample. In contrast, DNA from other viruses, such as CMV, EBV, HHV‐7, adenovirus, and HBV was never detected in any of the seven patients throughout the study period. Quantitative measurement of whole blood HHV‐6 DNA levels demonstrated four of the six HHV‐6 DNA loads were elevated at successive time points during the CNS dysfunction. In addition, the virus DNA peaks were temporally associated with the development of CNS dysfunction. CSF was tested in two of the four patients and high HHV‐6 DNA levels comparable to those in whole blood were confirmed in both. These four patients were, thus, suspected to have developed HHV‐6 encephalitis, a rate of 3.8% in the study population. Our results suggest that early diagnosis of probable HHV‐6 encephalitis can be improved by confirming high HHV‐6 DNA load in blood. J. Med. Virol. 88:319–323, 2016. © 2015 Wiley Periodicals, Inc.
Authenticity of rice (Oryza sativa L.) geographical origin based on analysis of C, N, O and S stable isotope ratios: a preliminary case report in Korea, China and Philippine
Authors: Chung Ill‐Min , Kim Jae‐Kwang , Prabakaran Mayakrishnan , Yang Jin‐Hee , Kim Seung‐Hyun
Published: August 2015

BACKGROUND

Although rice (Oryza sativa L.) is the third largest food crop, relatively fewer studies have been reported on rice geographical origin based on light element isotope ratios in comparison with other foods such as wine, beef, juice, oil and milk. Therefore this study tries to discriminate the geographical origin of the same rice cultivars grown in different Asian countries using the analysis of C, N, O and S stable isotope ratios and chemometrics.

RESULTS

The δ15NAIR, δ18OVSMOW and δ34SVCDT values of brown rice were more markedly influenced by geographical origin than was the δ13CVPDB value. In particular, the combination of δ18OVSMOW and δ34SVCDT more efficiently discriminated rice geographical origin than did the remaining combinations. Principal component analysis (PCA) revealed a clear discrimination between different rice geographical origins but not between rice genotypes. In particular, the first components of PCA discriminated rice cultivated in the Philippines from rice cultivated in China and Korea.

CONCLUSION

The present findings suggest that analysis of the light element isotope composition combined with chemometrics can be potentially applicable to discriminate rice geographical origin and also may provide a valuable insight into the control of improper or fraudulent labeling regarding the geographical origin of rice worldwide. © 2015 Society of Chemical Industry
An assessment of feeding jejunostomy tube placement at the time of resection for gastric adenocarcinoma: A seven‐institution analysis of 837 patients from the U.S. gastric cancer collaborative
Authors: Dann Gregory C. , Squires Malcolm H. , Postlewait Lauren M. , Kooby David A. , Poultsides George A. , Weber Sharon M. , Bloomston Mark , Fields Ryan C. , Pawlik Timothy M. , Votanopoulos Konstantinos I. , Schmidt Carl R. , Ejaz Aslam , Acher Alexandra W. , Worhunsky David J. , Saunders Neil , Levine Edward A. , Jin Linda X. , Cho Clifford S. , Winslow Emily R. , Russell Maria C. , Cardona Kenneth , Staley Charles A. , Maithel Shishir K.
Published: August 2015

Background

Jejunostomy feeding tubes (J‐tubes) are often placed during resection for gastric adenocarcinoma (GAC). Their effect on postoperative complications and receipt of adjuvant therapy is unclear.

Methods

Patients who underwent curative‐intent resection of GAC at seven institutions of the U.S. Gastric Cancer Collaborative from 2000 to 2012 were identified. The associations of J‐tubes with postoperative complications and receipt of adjuvant therapy were determined.

Results

Of 837 patients, 265 (32%) received a J‐tube. Patients receiving J‐tubes demonstrated greater incidence of preoperative weight loss, lower BMI, greater extent of resection, and more advanced TNM stage. J‐tube placement was associated with increased infectious complications (36% vs. 19%; P < 0.001), including surgical‐site (14% vs. 6%; P < 0.001) and deep intra‐abdominal (11% vs. 4%; P < 0.001) infections. On multivariate analysis, J‐tubes remained independently associated with increased risk of infectious complications (all: HR = 1.93; P = 0.001; surgical‐site: HR = 2.85; P = 0.001; deep intra‐abdominal: HR = 2.13; P = 0.04). J‐tubes were not associated with increased receipt of adjuvant therapy (HR = 0.82; P = 0.34). Subset analyses of patients undergoing total and subtotal gastrectomy similarly demonstrated an association of J‐tubes with increased risk of infectious outcomes and no association with increased receipt of adjuvant therapy.

Conclusions

J‐tube placement after resection of gastric adenocarcinoma is associated with increased postoperative infectious outcomes and is not associated with increased receipt of adjuvant therapy. Selective use of J‐tubes is recommended. J. Surg. Oncol. 2015 111:195–202. © 2015 Wiley Periodicals, Inc.
Rain Use Efficiency, Primary Production and Rainfall Relationships in Desert Rangelands of Tunisia
Authors: Gamoun Mouldi
Published: August 2015

Desert rangelands are characterised by low and highly variable rainfall regime, low forage production and high heterogeneity in the distribution of natural resources. This study was carried out in the desert rangelands of Tunisia to evaluate the response of different rangelands to annual rainfall in terms of aboveground net primary production (ANPP) and rain use efficiency over a 10‐year period (2003–2012). In general, ANPP values were relatively low (123 kg DM ha−1 y−1) but would tend to increase with increasing annual rainfall for all rangeland types. The highest value of ANPP was observed from Stipagrostis pungens and Hammada shmittiana communities (sandy‐soil) during the wet year 2011. In contrast, rain use efficiency tends to decline with the highest annual rainfall and varies among rangeland types and with an average of 1·9 kg DM ha−1 mm−1 y−1. Rain use efficiency tended to be higher during dry years and lower during wet years and tended to be higher on S. pungens and H. shmittiana (sandy‐soils) and lower on Helianthemum kahiricum (loamy soils). Therefore, understanding how rainfall affects productivity in rangelands is critical for predicting the impact of land degradation on the functioning of these ecosystems. It can be used to explain production decline associated with desertification as well as to assess rangeland conditions. Copyright © 2015 John Wiley & Sons, Ltd.
Star‐Shaped, Biodegradable, and Elastomeric PLLA‐PEG‐POSS Hybrid Membrane With Biomineralization Activity for Guiding Bone Tissue Regeneration
Authors: Xie Meihua , Ge Juan , Lei Bo , Zhang Qian , Chen Xiaofeng , Ma Peter X.
Published: August 2015

Multi‐armed biodegradable polymers have attracted much attention in biomedical applications, due to their special structure and properties. However, multi‐armed organic‐inorganic hybrids with high mechanical properties and biomineralization activity have not been reported yet. Here, star‐shaped poly‐L‐lactide‐poly (ethylene glycol)‐polyhedral oligomeric silsesquioxane (SPPS) hybrid membranes are fabricated for the first time for guiding bone regeneration applications by a photo‐crosslinking method using inositol as a core. SPPS demonstrates tunable mechanical properties (5.8 ± 0.2∼130 ± 23 MPa in tensile modulus, 30 ± 6%∼144 ± 13% in elongation, beyond 90% recovery), biodegradation, biomineralization activity and good osteoblast biocompatibility. These results suggest that our hybrids membrane may have promising applications in guiding bone regeneration.
Hepatic and visceral adipose tissue 11βHSD1 expressions are markers of body weight loss after bariatric surgery
Authors: Pardina Eva , Baena‐Fustegueras Juan Antonio , Fort José Manuel , Ferrer Roser , Rossell Joana , Esteve Montserrat , Peinado‐Onsurbe Julia , Grasa Mar
Published: August 2015

Objective

Cortisolemia and 11βHSD1 in liver and adipose tissue are altered in obesity. However, their participation in the development of obesity remains unclear. This study analyzed these parameters in the transition from morbid to type 1 obesity after bariatric surgery.

Methods

A group of 34 patients with morbid obesity and 22 nonobese subjects were recruited. Initial hypothalamus‐pituitary‐adrenal (HPA) basal activity and 11βHSD1 mRNA expression in liver, subcutaneous (SAT), and visceral adipose tissue (VAT) were evaluated. A year after bariatric surgery (weight loss of 48 kg), these parameters were reappraised in plasma, SAT, and liver.

Results

Body weight loss was accompanied by a downshift in basal HPA activity and 11βHSD1 expression in SAT. In patients with morbid obesity, 11βHSD1 expression correlated positively with BMI in VAT and negatively in liver at 6 and 12 months after surgery. In SAT, a correlation was observed with body weight only when patients showed type 1 obesity. Insulin, glucose, and HOMA correlated positively with all the HPA indicators and 11βHSD1 expression in SAT.

Conclusions

Body weight loss after bariatric surgery is accompanied by a downshift in basal HPA activity. Hepatic and VAT 11βHSD1 expressions in morbid obesity are predictors of body weight loss.
Visceral adiposity in persons with chronic spinal cord injury determined by dual energy X‐Ray absorptiometry
Authors: Cirnigliaro Christopher M. , LaFountaine Michael F. , Dengel Donald R. , Bosch Tyler A. , Emmons Racine R. , Kirshblum Steven C. , Sauer Sue , Asselin Pierre , Spungen Ann M. , Bauman William A.
Published: August 2015

Objective

To determine visceral adipose tissue (VAT) volume (VATvol) by dual energy X‐ray absorptiometry (DXA) in spinal cord injured (SCI) and able‐bodied (AB) participants and to explore the relationships between VATvol and routine anthropometric measures.

Methods

Sixty‐three subjects with SCI and 126 healthy male AB controls were stratified as low risk [LR: waist circumference (WC) < 102 cm] and moderate to high risk (MHR: WC ≥ 102 cm) for identification of risk for cardiometabolic disease: AB‐LR, SCI‐LR, AB‐MHR, and SCI‐MHR. Anthropometrics and standard body composition measurements by DXA with analysis to derive VATvol were performed.

Results

Comparison of the four subgroups demonstrated the highest subcutaneous adipose tissue volume (SATvol) in the AB‐MHR group (P < 0.01), and the highest VATvol in the SCI‐MHR group (P < 0.01). Furthermore, when compared to the AB group, participants with SCI had a 27% increase in VATvol for every centimeter increase in WC and a 20% increase in VATvol for every unit increase in BMI.

Conclusions

Because cutoff values for the routine surrogate measures of adiposity underestimate visceral adiposity in persons with SCI, the risk of adverse metabolic consequences would also be underestimated, which necessitates adjustment of the these cutoff values or, preferably, to perform its direct measurement.
Processing, structure, and properties of gel spun PAN and PAN/CNT fibers and gel spun PAN based carbon fibers
Authors: Newcomb Bradley A. , Gulgunje Prabhakar V. , Gupta Kishor , Kamath Manjeshwar G. , Liu Yaodong , Giannuzzi Lucille A. , Chae Han Gi , Kumar Satish
Published: August 2015

Polyacrylonitrile (PAN) and PAN/carbon nanotube (PAN/CNT) fibers were manufactured through dry‐jet wet spinning and gel spinning. Fiber coagulation occurred in a solvent‐free or solvent/nonsolvent coagulation bath mixture with temperatures ranging from −50 to 25°C. The effect of fiber processing conditions was studied to understand their effect on the as‐spun fiber cross‐sectional shape, as well as the as‐spun fiber morphology. Increased coagulation bath temperature and a higher concentration of solvent in the coagulation bath medium resulted in more circular fibers and smoother fiber surface. as‐spun fibers were then drawn to investigate the relationship between as‐spun fiber processing conditions and the drawn precursor fiber structure and mechanical properties. PAN precursor fiber tows were then stabilized and carbonized in a continuous process for the manufacture of PAN based carbon fibers. Carbon fibers with tensile strengths as high as 5.8 GPa and tensile modulus as high as 375 GPa were produced. The highest strength PAN based carbon fibers were manufactured from as‐spun fibers with an irregular cross‐sectional shape produced using a −50°C methanol coagulation bath, and exhibited a 61% increase in carbon fiber tensile strength as compared to the carbon fibers manufactured with a circular cross‐section. POLYM. ENG. SCI., 55:2603–2614, 2015. © 2015 Society of Plastics Engineers
High‐performance fibers based on copolyimides containing benzimidazole and ether moieties: Molecular packing, morphology, hydrogen‐bonding interactions and properties
Authors: Zhang Mengying , Niu Hongqing , Chang Jingjing , Ge Qiyan , Cao Li , Wu Dezhen
Published: August 2015

High‐performance copolyimide (co‐PI) fibers were prepared via the wet spinning process of co‐polyamide acid precursors based on 3,3′,4,4′‐biphenyldianhydride (BPDA) and a mixture of three diamines namely p‐phenylene diamine (p‐PDA), 2‐(4‐aminophenyl)‐5‐aminobenzimidazole (BIA), and 4,4′‐oxidianiline (ODA), followed by drawing and imidization at high temperatures. Effects of the ODA and BIA contents on the molecular packing, morphology, hydrogen‐bonding interactions, mechanical and thermal properties of the prepared fibers were investigated. The mechanical properties of the co‐PI fibers were improved with the addition of ODA and BIA, and they reached the optimum tensile strength of 2.7 GPa and modulus of 94.3 GPa. Wide‐angle X‐ray diffraction results (WAXD) showed that the co‐PI fibers exhibited highly oriented structure along the fiber direction with low degree of lateral packing orders in the transverse direction. Two‐dimensional small‐angle X‐ray scattering (2D‐SAXS) revealed that the incorporation of ODA resulted in the reduction in radius, length, misorientation, and internal surface roughness of the microvoids in the fibers. Fourier transform infrared (FTIR) results indicated that hydrogen‐bonding formed between the BIA and cyclic imide units effectively strengthened the intermolecular interactions. The co‐PI fibers exhibited excellent thermal and thermal‐oxidative stability, with a 5%‐weight‐loss temperature of 578°C under N2 and 572°C in air. POLYM. ENG. SCI., 55:2615–2625, 2015. © 2015 Society of Plastics Engineers
Patient reporting pain intensity immediately after surgery can be associated with underlying depression in women with breast cancer
Authors: Kim Yoo Seok , Do Hyuigyung , Lee Jong Won , Jeong Jaesim , Shin Yong Wook , Yi Kikyoung , Kim Jisun , Lee Sae Byul , Sohn Guiyun , Yang Nuri , Oh Youngkyung , Kim Leeyoung , Kim Yeonhee , Yu Jong Han , Ko Beom Seok , Kim Hee Jeong , Son Byung Ho , Ahn Sei Hyun
Published: August 2015

Objective

The aims of this study were to determine the prevalence of severe, definite depression symptoms, as measured using the Center for Epidemiological Studies Depression Scale (CES‐D), and the association between high CES‐D scores (i.e., ≥25) and sociodemographic and perioperative factors during perioperative period.

Methods

Among 1690 consecutive breast cancer patients who were admitted for definitive breast surgery during the study period, 1499 patients were included in this study. Patients with a past medical history of psychiatric medication or support, a plan for elective surgery due to locoregional recurrence, or any metastatic disease were excluded. The CES‐D score was checked 1 day before definitive surgeries. The sociodemographic data and perioperative data were analyzed.

Results

The mean CES‐D score was 18.5, with 24.1% (362/1499) and 56.7% (850/1499) having high CES‐D scores of ≥25 and ≥16, respectively. Multivariate analysis revealed that the number of family members with any malignancy (≥2 vs. 0), sedative medication (yes vs. no), and postoperative numeric rating scale scores (persistent, severe pain vs. stably mild pain) were significantly associated factors for severe, definite depression symptoms [CES‐D score of ≥25: adjusted odds ratio (OR) = 1.56, 95% confidence interval (CI) = 1.10–2.21, p = 0.013; adjusted OR = 1.65, 95% CI = 1.00–2.71, p = 0.048; and adjusted OR = 2.14, 95% CI = 1.15–3.95, p = 0.016, respectively].

Conclusion

Depression may increase the intensity of postoperative acute pain. Self‐reporting of persistent postoperative pain intensity is potentially useful in detecting hidden depression symptoms in breast cancer patients during the perioperative period. Copyright © 2015 John Wiley & Sons, Ltd.
β1 Adrenoceptor antagonistic effects of the supposedly selective β2 adrenoceptor antagonist ICI 118,551 on the positive inotropic effect of adrenaline in murine hearts
Authors: Pecha Simon , Flenner Frederik , Söhren Klaus‐Dieter , Lorenz Kristina , Eschenhagen Thomas , Christ Torsten
Published: August 2015

Studies on the relative contribution of β1‐ and β2‐adrenoceptors (AR) generally employ selective β1‐ and β2‐AR antagonists such as CGP 20712A and ICI 118,551, respectively, and assume that antagonism by one of these compounds indicates mediation by the respective AR subtype. Here, we evaluated the β2‐AR‐selectivity of ICI 118,551 in ventricular muscle strips of transgenic mice lacking β1‐AR (β1‐KO), β2‐AR (β2‐KO), or both (β1/β2‐KO). Strips were electrically driven and force development was measured. In wild type (WT), ICI 118,551 (100 nmol/L) shifted the concentration–response curve (CRC) for adrenaline by about 0.5 log units to the right, corresponding to the known affinity of ICI 118,551 to β1‐AR but not to β2‐AR. Conversely, the phosphodiesterase inhibitor rolipram (10 μmol/L) shifted the CRC to the left, but did not enlarge the ICI 118,551 shift, indicating exclusive β1‐AR mediation even when PDE4 is inactive. In line with this, rolipram and ICI 118,551 had similar effects in β2‐KO than in WT. In contrast, β1‐KO did not show any inotropic reaction to adrenaline (+/− rolipram). In WT, the β1‐AR selective antagonist CGP 20712A (100 nmol/L) shifted the CRC for isoprenaline by 2.1 log units, corresponding to the affinity of CGP 20712A to β1‐AR. Rolipram increased the sensitivity to adrenaline independently of the presence of CGP 20712A. We conclude that effects sensitive to the β2‐AR antagonist ICI 118,551 are not necessarily β2‐AR‐mediated and CGP 20712A‐resistant effects cannot be simply interpreted as β2‐AR‐mediated. Catecholamine effects in murine ventricles strictly depend on β1‐AR, even if PDE 4 is blocked.
Preparation and study of the thermoelectric properties of nanocrystalline Sn1−xTaxO2 (0 ≤ x ≤ 0.04)
Authors: Vo Thi Thanh Xuan , Le Thi Ngoc Ha , Pham Quoc Nghi , Byl Céline , Dragoe Diana , Barthés‐Labrousse Marie‐Geneviève , Bérardan David , Dragoe Nita
Published: August 2015

Sn1–xTaxO2 (0 ≤ xnominal ≤ 0.04) nanoparticles, smaller than 10 nm, were synthesized by co‐precipitation method. The solubility limit of Ta (about 0.8% mol) was carefully studied by combination of XRD, SEM, and ICP analysis. The obtained powders were sintered by using the spark plasma sintering (SPS) technique, leading to dense pellets (∼95–97% density), composed of 50–70 nm grains. XPS results suggest that no Sn2+ is present in our samples and that the carbon contamination as well as oxygen vacancies, issues from SPS, are not completely removed with a post‐SPS heat treatment at 873 K. However, this small carbon contamination does not significantly influence the electrical properties. Thermoelectric properties were investigated and the best composition was found to be Sn0.99Ta0.01O2 (x = 0.01), with ρ = 4 × 10−3 Ωcm, S = −46 μVK−1, and κ ∼ 7 WK−1 m−1, at room temperature. This low thermal conductivity, as compared to those of micro‐sized SnO2‐based materials in the literature, is explained by the nanocrystalline character of the samples.
Revisiting the broadband dielectric properties of high‐sensitivity piezoelectric BiScO3–PbTiO3: Size effects
Authors: Balčiūnas S. , Ivanov M. , Grigalaitis R. , Banys J. , Amorín H. , Castro A. , Algueró M.
Published: August 2015

The dielectric properties of high‐temperature piezoelectric 0.36BiScO3–0.64PbTiO3 ceramics located at the morphotropic phase boundary with decreasing average grain sizes from 1.6 μm down to 26 nm were investigated in the 100–500 K temperature range and 100 Hz–40 GHz frequency region. Analysis of the current data and comparison with results of Porokhonskyy et al. [Appl. Phys. Lett. 83, 1605 (2003)] allows a deeper understanding of the polarization mechanisms in the system to be obtained. The main contribution to dielectric permittivity comes from the dynamics of polar nanoregions embedded into the ferroelectric matrix. Domain walls give significant contribution to permittivity in the case of submicrometer grains. A process related to coupling of polarization to strain is observed at microwave frequencies. Its characteristic frequency scales inversely proportional to grain size and is not dependent on domain thickness.
Preparation and nonlinear optical properties of LiCaBO3–Ag2O and LiCaBO3–Gd2O3–Ag2O borate glasses with Ag nanoparticles
Authors: Dutka R. M. , Adamiv V. T. , Burak Ya. V. , Gamernyk R. V. , Teslyuk I. M.
Published: August 2015

The preparation and results of investigations of nonlinear optical properties of LiCaBO3–Ag2O and LiCaBO3–Gd2O3–Ag2O glasses with Ag nanoparticles (Ag NPs) formed by thermal treatment in vacuum and in air are presented. The intensive plasmon absorption Ag NPs in optical transmission spectra were observed. Nonlinear optical properties of glasses by single‐beam Z‐scan technique were investigated: it was ascertained an influence of Ag NPs on their nonlinear optical properties, in particular, changes of nonlinear refractive index n2, and nonlinear absorption coefficient β.
Interaction of oxygen vacancy and its impact on transmission coefficient in oxygen‐deficient titanium dioxide: Ab initio calculations
Authors: Li Lei , Li Wenshi , Ji Aimin , Wang Ziou , Zhu Canyan , Zhang Lijun , Yang Jianfeng , Mao Ling‐Feng
Published: August 2015

Ab initio calculations on the interaction of the oxygen vacancy and its impact on the transmission coefficients in oxygen‐deficient TiO2 are reported. It is found that the separated oxygen vacancies or divacancies produce partial shallow defect energy levels below the conduction‐band edge as weak interactions between these vacancies. On the contrary, for the ordering oxygen divacancies, we observe that the defect energy levels fill in the bandgap. A much higher extent is found for the ordering oxygen divacancies in both columns of the supercell due to the appearance of many reduced Ti3+ ions. As a result, these oxygen divacancies expand the transmission range and improve the transmission coefficients. The microscopic origin of the oxygen‐vacancy interaction is helpful to clarify the mechanism of the resistive switching phenomenon.
Stahlguss im Bauwesen
Authors: Spannaus Max , Ummenhofer Thomas
Published: August 2015

Beim Einsatz von Stahlguss muss der Tragwerksplaner schon in der Entwurfs‐ und Planungsphase die innere Beschaffenheit eines Bauteils festlegen, da diese den rechnerisch ansetzbaren Bauteilwiderstand direkt beeinflusst. Aufgrund unzureichender normativer Regelung fehlt jedoch eine Entscheidungsgrundlage, sodass aus technischen Gesichtspunkten oftmals eine zu hohe Gütestufe verlangt wird, die die Herstellungskosten erhöht. Im Rahmen eines aktuellen Forschungsprojekts an der Versuchsanstalt für Stahl, Holz und Steine des Karlsruher Instituts für Technologie soll die Grundlage für die Erweiterung der bestehenden Regelwerke auf Basis experimenteller und numerischer Untersuchungen geschaffen werden. Ziel ist die Erarbeitung einer Bemessungsgrundlage, die den direkten Zusammenhang zwischen Ausnutzungsgrad, Bauteildicke und benötigter Gütestufe herstellt. Dieser Beitrag rezensiert den aktuellen Stand der technischen Baubestimmungen und gibt einen Überblick über den Stand der bisherigen Arbeiten im Forschungsprojekt.

Cast steel in civil engineering. The structural engineer already has to determine during the design and planning phase the internal condition of a component by using cast steel, because it directly influences the mathematically calculated component resistance. However, due to insufficiently normative regulations a basis for decisions lacks, so that from technical aspects a too high quality grade is often demanded that increases manufacturing costs. Within the scope of a current research project at the Research Center for Steel, Timber and Masonry at Karlsruhe Institute of Technology, Germany, a foundation for an expansion of the existing regulations based on experimental and numerical investigations is to be provided. The aim is the development of an assessment base that establishes the direct relation between stress ratio, thickness of component and required quality grade. This contribution reviews the current status of the technical building regulations and gives an overview of the status of the work in the research project carried out so far.
Vereinfachtes Verfahren für den Beulnachweis bei Ausnutzung plastischer Querschnittsreserven durch Einführung einer “wirksamen Blechdicke“
Authors: Naumes Johannes , Geißler Karsten , Bartzsch Matthias
Published: August 2015

Durch die Einführung einer “wirksamen Blechdicke“ werden die beiden im Eurocode 3‐1‐5 enthaltenen Verfahren zum Nachweis der Beulsicherheit ineinander überführt. Das Ergebnis ist ein zweistufiges Verfahren, das die Einfachheit der Methode der reduzierten Spannungen und die Wirtschaftlichkeit der Methode der wirksamen Breiten in sich vereint. Dieses bereits in der Zeitschrift Stahlbau [4] vorgestellte vereinfachte Verfahren wird hier anhand eines Praxisbeispiels ausführlich erläutert und diskutiert.

Simplified Method to exploit the plastic buckling resistance by introducing an effective plate thickness – explanations and examples. By introducing an effective plate‐thickness both approaches of the Eurocode 3‐1‐5 to calculate the buckling resistance are merged together. The outcome is a two‐step method, which combines the ease of use of the reduced stress method and the high cross‐section resistances of the effecticvep width method. This simplified method, which have already been presented in the journal Stahlbau [4], is demonstrated and discussed in detail by a practical example.
Epoxy‐ and acrylic‐bonded joints for strengthening lightweight steel girders
Authors: Sahellie Samer , Pasternak Hartmut
Published: August 2015

Several attempts have been made to introduce the adhesive bonding technique into steel construction, showing that this technique is promising and could replace traditional joining methods such as bolts, rivets and welding. Epoxy adhesive is used for structural joints more than acrylic due to its advanced properties such as its high capacity and its relatively good resistance to aging and environmental effects when compared with acrylic.

The following paper briefly shows the difference between the use of epoxy and acrylic adhesives when bonding steel plates to strengthen lightweight cold‐formed galvanized steel girders. The thickness of the adhesive layers is 0.65 mm. Strengthened girders were tested experimentally at room temperature (20 °C) in 3‐point bending tests and numerically investigated at –20 °C and 40 °C. The results show the efficiency of the bonded strengthening joints and that acrylic has an advantage in that it can absorb the deformations of the ductile steel without breaking.

Verstärkung von Stahlleichtbauprofilen durch Epoxid‐ und Acrylat‐Klebverbindungen. Bei der Untersuchung von Klebverbindungen im Stahlleichtbau hat sich gezeigt, dass diese Technik erfolgversprechend ist und die traditionellen Fügetechniken, wie Schrauben, Nieten und Schweißen, ersetzen kann. Epoxidklebstoff wird bei Stahlverbindungen häufiger verwendet als Acrylatklebstoff, da dieser bessere Eigenschaften wie hohe Festigkeit, relativ gute Alterungsbeständigkeit und Umweltauswirkungen hat.

Der Beitrag zeigt am Beispiel der Verstärkung eines verzinkten Stahlleichtbauprofils den Unterschied zwischen Epoxid‐ und Acrylatklebstoffen. Die Dicke der Klebstoffschicht beträgt 0,65 mm. Der verstärkte Träger wird bei Raumtemperatur (20 °C) im 3‐Punkt‐Biegeversuch getestet und numerisch bei Temperaturen von –20 °C und 40 °C simuliert. Die Ergebnisse zeigen, dass die durch Kleben verstärkte Verbindung effektiv ist. Acrylat‐Klebverbindungen haben den Vorteil, dass sie die Verformungen des duktilen Stahls ohne Bruch aufnehmen können.
Zur Ermüdungsfestigkeit von feuerverzinkten Zugstäben mit Endgewinden
Authors: Unglaub Julian , Reininghaus Matthias , Thiele Klaus
Published: August 2015

Es ist bekannt, dass das Fertigungsverfahren von Zugstäben mit Endgewinden einen großen Einfluss auf die Ermüdungsfestigkeit hat. Der Einfluss des Feuerverzinkens auf die Ermüdungsfestigkeit ist jedoch weniger bekannt. Es werden die Ergebnisse von Ermüdungsversuchen an geschnittenen, gerollten, gerollt feuerverzinkten und feuerverzinkt gerollten Zugstangen mit Endgewinden präsentiert und diskutiert.

Fatigue of tension rods with hot dipped galvanized threads. It is known that the manufacturing process of tension rods with threads has a great influence on the fatigue strength. The impact of hot‐dip galvanized tension rods on the fatigue strength is less well known. The results of fatigue tests of cut, rolled, rolled hot dipped galvanized and hot dipped galvanized rolled threads will be presented and discussed.
Synthesis, Structure, and Photoluminescence Properties of an Organically‐Templated Uranyl Selenite
Authors: Liu Dong‐Sheng , Kuang Han‐Mao , Chen Wen‐Tong , Luo Qiu‐Yan , Sui Yan
Published: August 2015

The organically‐templated uranyl selenite, (H2en)[(UO2)(SeO3)(HSeO3)](NO3)·0.5H2O (1) (en = 1,2‐ethylenediamine) was synthesized and characterized by elemental analyses, IR spectroscopy, TG, and single‐crystal X‐ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group Pbca, with a = 13.170(3) Å, b = 11.055(2) Å, c = 18.009(4) Å, V = 2621.8(9) Å3, M = 1316.19, Z = 4, Dcal = 3.334 g·cm–3, μ(Mo‐Kα) = 17.998 mm–1, GOF = 1.059, R1 = 0.0263, wR2 = 0.0532 [I>2σ(I)]. The X‐ray diffraction analysis reveals that compound 1 has a three‐dimensional (3D) supramolecular structure. It contains negatively charged [UO2(HSeO3)(SeO3)]– inorganic anion layers and is balanced by [H2en]2+ cations and NO3– anions located in the interlayers. Furthermore, the photoluminescence properties of 1 were investigated.
Clinical Outcomes of Carotid Endarterectomy in Symptomatic and Asymptomatic Patients with Ipsilateral Intracranial Stenosis
Authors: Ballotta Enzo , Toniato Antonio , Da Roit Anna , Baracchini Claudio
Published: August 2015

Background and purpose

The risk of perioperative stroke and the benefits of carotid endarterectomy (CEA) remain uncertain in the case of an ipsilateral intracranial stenosis. The aim of this observational study was to analyze the early and late outcomes of CEA in patients with a carotid tandem lesion (CTL), defined as a severe stenosis at the bifurcation with any concomitant lesion ≥50 % involving the intracranial portion of the ipsilateral internal carotid artery or the main trunk of the anterior or middle cerebral artery.

Methods

From 2000 to 2009, 1143 patients underwent CEA for symptomatic or asymptomatic extracranial carotid stenosis according to the NASCET and ACAS recommendations, respectively. CTLs were diagnosed in 219 patients (19.2 %) by extracranial and transcranial color‐coded Doppler sonography combined with noninvasive brain imaging studies. The primary endpoints of the study were perioperative (30‐day) stroke and death, and any ipsilateral ischemic adverse events during the follow‐up, which ranged from 0.1 to 10 years (mean 4.9 ± 3.3 years). The rates of the primary endpoints were compared between patients with (group I) and without CTL (group II).

Results

Overall, 219 CEAs were performed in group I and 924 in group II. Nearly two in three of the carotid lesions (777 of 1143, 68 %) were symptomatic at presentation (62.1 % in group I vs 69.4 % in group II; p = 0.03), with a 23.8 % rate of stroke (21.9 % in group I vs 24.2 % in group II; p = 0.85). There were 2 (0.9 %) perioperative ipsilateral strokes in group I and 5 (0.5 %) in group II (p = 0.62), and no deaths. The 5‐year ipsilateral stroke‐free, any stroke‐free, and overall survival rates did not differ significantly between patients with and without CTL.

Conclusions

This study has shown that patients with and without CTL who underwent CEA had a similar occurrence of perioperative adverse events (probably due to the extremely low incidence of perioperative complications) and comparable late outcomes, suggesting that the presence of CTL does not justify refusing CEA for patients who could benefit from it.
Functional manipulations of the tetramycin positive regulatory gene ttmRIV to enhance the production of tetramycin A and nystatin A1 in Streptomyces ahygroscopicus
Authors: Cui Hao , Ni Xianpu , Shao Wei , Su Jian , Su Jiaqi , Ren Jun , Xia Huanzhang
Published: August 2015

A putative regulatory gene ttmRIV located in the tetramycin biosynthetic gene cluster was found in Streptomyces ahygroscopicus. In-frame deletion of ttmRIV led to abolishment of tetramycin and significant enhancement of nystatin A1, whose production reached 2.1-fold of the H42 parental strain. Gene complementation by an integrative plasmid carrying ttmRIV restored tetramycin biosynthesis revealed that ttmRIV was indispensable to tetramycin biosynthesis. Gene expression analysis of the H42 strain and its mutant strain ΔttmRIV via reverse transcriptase-PCR of the tetramycin gene cluster demonstrated that the expression levels of most biosynthetic genes were reduced in ΔttmRIV. Results of electrophoretic mobility shift assays showed that TtmRIV bound the putative promoters of several genes in the tetramycin pathway. Thus, TtmRIV is a pathway-specific positive regulator activating the transcription of the tetramycin gene cluster in S. ahygroscopicus. Providing an additional copy of ttmRIV under the control of the ermEp* promoter in the H42 strain boosted tetramycin A production to 3.3-fold.