bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of a Lorazepam Dose Threshold for Using the Osmol Gap to Monitor for Propylene Glycol Toxicity
Authors: Yahwak Jason A. , Riker Richard R. , Fraser Gilles L. , Subak‐Sharpe Sarah 
Published: July 2008

Study Objective. To determine a threshold dose for parenteral lorazepam when screening for propylene glycol toxicity with the osmol gap, and to characterize which osmol gap values are more predictive of toxic propylene glycol concentrations and resultant clinical toxicity.Design. Prospective, two‐phase observational study.Setting. Thirty‐two bed, multidisciplinary intensive care unit.Patients. Thirty‐five adult patients receiving any dose of parenteral lorazepam (phase 1), and 14 patients receiving lorazepam in doses of 1 mg/kg/day or higher (phase 2).Measurements and Main Results. Serum osmolality was measured every other day during lorazepam therapy, and the osmol gap (measured osmolality minus calculated osmolarity) was determined. A serum propylene glycol concentration was obtained when the osmol gap first exceeded 10. In phase 1, 35 patients were monitored for 186 patient‐days. Ten patients (29%) developed an osmol gap greater than 10; only one (10%) of these patients had propylene glycol concentrations greater than 18 mg/dl. In phase 2, 14 patients received lorazepam at a median dose of 631 mg (interquartile range [IQR] 437–972 mg) over a median of 5.5 days (IQR 4–8.75 days). Nine patients (64%) had propylene glycol concentrations greater than 18 mg/dl; six (67%) of these nine developed transient acute kidney injury, metabolic acidosis, or both. The correlation between osmol gap and propylene glycol concentration was 0.44 (p=0.006). An osmol gap of 10 or greater had a likelihood ratio of 4.4 to predict a propylene glycol concentration greater than 18 mg/dl. An osmol gap of 12 or greater had a likelihood ratio of 2.7 to predict the development of possible propylene glycol clinical toxicity.Conclusion. Screening for propylene glycol toxicity with the osmol gap may be helpful for patients receiving intravenous lorazepam in doses of 1 mg/kg/day or higher. An osmol gap of 10 or greater was predictive of elevated propylene glycol concentrations, and values of 12 or greater were predictive of clinical changes suggestive of propylene glycol toxicity.
A Stable Niche Supports Long-Term Maintenance of Human Epidermal Stem Cells in Organotypic Cultures
Authors: Muffler Sonja , Stark Hans-Jürgen , Amoros Mara , Falkowska-Hansen Berit , Boehnke Karsten , Bühring Hans-Jörg , Marmé Alexander , Bickenbach Jackie R. , Boukamp Petra 
Published: July 2008

Abstract
Stem cells in human interfollicular epidermis are still difficult to identify, mainly because of a lack of definitive markers and the inability to label human beings for label-retaining cells (LRCs). Here, we report that LRCs could be identified and localized in organotypic cultures (OTCs) made with human cells. Labeling cultures for 2 weeks with iododeoxyuridine (IdU) and then chasing for 6–10 weeks left &lt;1% of basal cells retaining IdU label. Whole mounts demonstrated that LRCs were individually dispersed in the epidermal basal layer. Some LRCs, but not all, colocalized with cells expressing melanoma chondroitin sulfate proteoglycan, a putative stem cell marker. Although we found LRCs in both collagen- and scaffold-based OTCs, only the scaffold-OTCs supported long-term survival and regeneration. LRCs' short survival in collagen-OTCs was not due to loss of appropriate growth factors from fibroblasts. Instead, it was due to expression of metalloproteinases, especially matrix metalloproteinase (MMP)-2 and MMP-14, which caused collagen fragmentation, matrix degradation, and dislocation of specific basement membrane components bound to epidermal integrins. Blocking MMP activation not only abrogated MMP-dependent matrix degradation but also increased longevity of the epidermis and the LRCs in these cultures. Such findings indicate that the stem cell niche, the microenvironment surrounding and influencing the stem cell, is essential for stem cell survival and function, including long-term tissue regeneration.
Disclosure of potential conflicts of interest is found at the end of this article.
Autophagic Death of Adult Hippocampal Neural Stem Cells Following Insulin Withdrawal
Authors: Yu Seong-Woon , Baek Seung-Hoon , Brennan Ryan T. , Bradley Christopher J. , Park Se Kyong , Lee Yoon Sun , Jun Eun Jung , Lookingland Keith J. , Kim Eun-Kyoung , Lee Heuiran , Goudreau John L. , Kim Seong Who 
Published: July 2008

Abstract
Novel therapeutic approaches using stem cell transplantation to treat neurodegenerative diseases have yielded promising results. However, survival of stem cells after transplantation has been very poor in animal models, and considerable efforts have been directed at increasing the viability of engrafted stem cells. Therefore, understanding the mechanisms that regulate survival and death of neural stem cells is critical to the development of stem cell-based therapies. Hippocampal neural (HCN) stem cells derived from the adult rat brain undergo cell death following insulin withdrawal, which is associated with downregulation of antiapoptotic Bcl-2 family members. To understand the type of cell death in HCN cells following insulin withdrawal, apoptosis markers were assessed. Of note, DNA fragmentation or caspase-3 activation was not observed, but rather dying cells displayed features of autophagy, including increased expression of Beclin 1 and the type II form of light chain 3. Electron micrographs showed the dramatically increased formation of autophagic vacuoles with cytoplasmic contents. Staurosporine induced robust activation of caspase-3 and nucleosomal DNA fragmentation, suggesting that the machinery of apoptosis is intact in HCN cells despite the apparent absence of apoptosis following insulin withdrawal. Autophagic cell death was suppressed by knockdown of autophagy-related gene 7, whereas promotion of autophagy by rapamycin increased cell death. Taken together, these data demonstrate that HCN cells undergo a caspase-independent, autophagic cell death following insulin withdrawal. Understanding the mechanisms governing autophagy of adult neural stem cells may provide novel strategies to improve the survival rate of transplanted stem cells for treatment of neurodegenerative diseases.
Disclosure of potential conflicts of interest is found at the end of this article.
Enhanced Cooperativity in Hydrolytic Kinetic Resolution of Epoxides using Poly(styrene) Resin‐Supported Dendronized Co‐(Salen) Catalysts
Authors: Goyal Poorva , Zheng Xiaolai , Weck Marcus 
Published: July 2008

AbstractExcellent enantioselectivities and isolated yields have been achieved for the hydrolytic kinetic resolution of epoxides using a resin‐supported dendronized R,R‐(salen)Co catalyst with catalyst loadings as low as 0.04 mol%, the lowest metal loadings of any heterogeneous resin‐supported (salen)Co catalyst reported to date. In addition, the supported catalysts can be recycled and reused with comparable enantioselectivities. It is hypothesized that the high catalytic activity can be attributed to the flexible linker and the dendronized framework supporting the (salen)Co moieties on the resin thereby promoting cooperativity between two metal centers. This work opens up new opportunities for the design of highly active resin‐supported catalysts that catalyze transformations through a bimetallic pathway.
Bromodimethylsulfonium Bromide‐Silver Triflate: A New Powerful Promoter System for the Activation of Thioglycosides
Authors: Xiong De‐Cai , Zhang Li‐He , Ye Xin‐Shan 
Published: July 2008

AbstractBromodimethylsulfonium bromide (BDMS) in combination with silver triflate provides a very efficient thiophilic promoter system, capable of activating both “disarmed” and “armed” thioglycosides for glycosidic bond formation. The usefulness of this new promoter is illustrated by a successful reactivity‐based one‐pot oligosaccharide assembly.
Animal models of ventral body wall closure defects: A personal perspective on gastroschisis
Authors: Williams Trevor 
Published: July 2008

AbstractMalformations affecting the ventral body wall comprise one of the leading categories of human birth defects. Gastroschisis is a particularly important body wall closure defect as its incidence is rising worldwide. Although the occurrence of such defects is relatively common their molecular and cellular basis is very poorly understood. A robust animal model system to study the etiology of gastroschisis would be very useful, but several problems currently hamper the identification of such a model. A concerted effort is required to recognize, characterize, and classify ventral body wall defects in animal model species so that progress can be made in determining the mechanisms of ventral body wall closure during human development as well as combating the increased incidence of gastroschisis worldwide. © 2008 Wiley‐Liss, Inc.
Gastroschisis: International epidemiology and public health perspectives
Authors: Castilla Eduardo E. , Mastroiacovo Pierpaolo , Orioli Iêda M. 
Published: July 2008

AbstractGastroschisis offers the intriguing epidemiological situation of a pandemic, strongly associated with very low maternal age. Identifying gastroschisis, and distinguishing it from the other abdominal wall defects, is theoretically easy but difficult in practice. The baseline birth prevalence of gastroschisis before the pandemic was approximately 1 in 50,000 births and has increased since between 10‐ and 20‐fold. In many populations worldwide, it is still increasing. Such increasing prevalence and the association with very low maternal age are well proven, but the interaction between these two findings remains unknown. Geographic gradients (decreasing prevalence from North to South) are clear in Continental Europe and suggestive in Britain and Ireland. Gastroschisis seems more frequent in Caucasians compared to African Blacks and Orientals, and in Northern compared to Southern Europeans. These observations indicate the need for investigating gene–environment interactions. Since the global human situation is marked by inequalities among as well as within countries, the medical care and public health impact of gastroschisis varies widely among regions and social strata. The postnatal benefits of prenatal diagnosis of gastroschisis include family awareness; adequate planning of delivery with alerted obstetrical, pediatric, and surgical staff; optimal risk categorization, and personalized protocol for action. The increasing prevalence of gastroschisis combined with improved medical techniques to reduce morbidity and mortality are also increasing the burden and costs of this anomaly on health systems. © 2008 Wiley‐Liss, Inc.
Gastroschisis: A gene–environment model involving the VEGF–NOS3 pathway
Authors: Lammer Edward J. , Iovannisci David M. , Tom Lauren , Schultz Kathy , Shaw Gary M. 
Published: July 2008

AbstractGastroschisis is a severe major malformation in which an infant is delivered with a portion of intestines and possible other abdominal organs extruding through a defect in the abdominal wall, usually to the right of the umbilical cord. Etiologies of gastroschisis are largely unknown, and even its pathogenesis is poorly understood. Several recent epidemiological studies have identified interactions between maternal smoking during pregnancy, genetic variants of endothelial nitric oxide synthase, and risk for gastroschisis. We present a brief review of the endothelial nitric oxide synthase pathway and its relationship to vasculogenesis, suggesting that disruption of this pathway by environmental exposures or by genetic variation may represent one pathogenetic model for gastroschisis. © 2008 Wiley‐Liss, Inc.
Ancient DNA analysis of human remains from the upper capital city of Kublai Khan
Authors: Fu Yuqin , Xie Chengzhi , Xu Xuelian , Li Chunxiang , Zhang Quanchao , Zhou Hui , Zhu Hong 
Published: July 2008

AbstractAnalysis of DNA from human archaeological remains is a powerful tool for reconstructing ancient events in human history. To help understand the origin of the inhabitants of Kublai Khan's Upper Capital in Inner Mongolia, we analyzed mitochondrial DNA (mtDNA) polymorphisms in 21 ancient individuals buried in the Zhenzishan cemetery of the Upper Capital. MtDNA coding and noncoding region polymorphisms identified in the ancient individuals were characteristic of the Asian mtDNA haplogroups A, B, N9a, C, D, Z, M7b, and M. Phylogenetic analysis of the ancient mtDNA sequences, and comparison with extant reference populations, revealed that the maternal lineages of the population buried in the Zhenzishan cemetery are of Asian origin and typical of present‐day Han Chinese, despite the presence of typical European morphological features in several of the skeletons. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Scaling of chew cycle duration in primates
Authors: Ross Callum F. , Reed David A. , Washington Rhyan L. , Eckhardt Alison , Anapol Fred , Shahnoor Nazima 
Published: July 2008

AbstractThe biomechanical determinants of the scaling of chew cycle duration are important components of models of primate feeding systems at all levels, from the neuromechanical to the ecological. Chew cycle durations were estimated in 35 species of primates and analyzed in conjunction with data on morphological variables of the feeding system estimating moment of inertia of the mandible and force production capacity of the chewing muscles. Data on scaling of primate chew cycle duration were compared with the predictions of simple pendulum and forced mass–spring system models of the feeding system. The gravity‐driven pendulum model best predicts the observed cycle duration scaling but isrejected as biomechanically unrealistic. The forced mass–spring model predicts larger increases in chew cycle duration with size than observed, but provides reasonable predictions of cycle duration scaling. We hypothesize that intrinsic properties of the muscles predict spring‐like behavior of the jaw elevator muscles during opening and fast close phases of the jaw cycle and that modulation of stiffness by the central nervous system leads to spring‐like properties during the slow close/power stroke phase. Strepsirrhines show no predictable relationship between chew cycle duration and jaw length. Anthropoids have longer chew cycle durations than nonprimate mammals with similar mandible lengths, possibly due to their enlarged symphyses, which increase the moment of inertia of the mandible. Deviations from general scaling trends suggest that both scaling of the jaw muscles and the inertial properties of the mandible are important in determining the scaling of chew cycle duration in primates. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Effect of temperature‐pressure cycles on structural properties of epoxy‐based composites for printed circuit boards applications
Authors: Fernandes Elizabeth G. , Tramidi Cristiano , Di Gregorio Giordano M. , Angeloni Giacomo , Chiellini Emo 
Published: July 2008

AbstractDuring multilayer printed circuit board production, cyclic pressure–temperature (P–T) treatments can give rise to mechanical and thermal stresses with subsequent inner delamination phenomena. These are mainly related to the thermomechanical properties of epoxy resins used in the manufacturing process. In this study, the physical and chemical changes of commercial epoxy‐based prepregs were investigated as a function of P–T treatments by means of thermogravimetric analysis, differential scanning calorimeter, and Fourier transform infrared‐photoacoustic spectroscopy. It was verified that the thermal properties start to decrease after the first P–T treatment. In connection, absorbance spectra indicated that the peaks at 2273 cm−1 and 2235 cm−1 (cyanate group) disappeared after this treatment. Heat transfer as a function of laminate thickness (consequently, as a function of P–T treatment) is one variable that probably contributes to the findings in the work. The results of this study indicated that the analytical methods were satisfactory to determine the beginning of the deterioration of the printed circuit as a function of the P–T treatments. They can be used as a reference for quality controls and to prevent mechanical problems such as interlaminar fractures in the relevant printed circuits. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and curing behavior of a novel ferrocene‐based epoxy compound
Authors: Yu Haojie , Wang Li , Huo Jia , Ding Jianhua , Tan Qiaohua 
Published: July 2008

AbstractA novel ferrocene‐based epoxy compound of glycidyl ester of 1,1′‐ferrocene dicarboxylate was synthesized by the reaction of 1,1′‐ferrocene dicarboxylate and epichlorohydrin. The resultant epoxy compound showed an irreversible redox process in cyclic voltammetry (CV) measurement. The curing behavior of glycidyl ester of 1,1′‐ferrocene dicarboxylate and dicyandiamide system was investigated by nonisothermal measurement using the Ozawa's approach with the heating rate of 5, 10, 15, and 20°C/min, respectively. It was found that both the diffusion of the compound and the curing temperature have effect on the curing process, and the effect of temperature was greater. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Diffusion of chloride ions in polymer‐mortar composites
Authors: Benosman A. S. , Taibi H. , Mouli M. , Belbachir M. , Senhadji Y. 
Published: July 2008

AbstractIn recent years, the rapid deterioration of various reinforced concrete structures has been a widely recognized problem in the world. Penetration of chloride ions into the concrete structures was found to be the major cause of premature corrosion of reinforcing steel and to promote their deterioration. The present articles deals with the resistance to chloride penetration of polymer‐mortar, which are often used as low‐cost promising materials for preventing or repairing various reinforced concrete structures. To gain more knowledge on the efficiency of polymer‐mortar, four mortar mixtures: one specimen with Portland cement (control sample) and three mixtures with 2.5, 5, and 7.5 wt % of the replacement of cement by polyethylene terephthalate (PET) were tested for chloride ion permeability under immersion in 5% sodium chloride solution. Their chloride ion penetration behavior is discussed by applying Fick's second law. In conclusion, the chloride ion penetration depth and apparent chloride ion diffusion coefficient of the polymer‐mortar composites are smaller than those of unmodified mortar. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymeric curing agent reinforced silicone rubber composites with low viscosity and low volume shrinkage
Authors: Dai Lina , Zhang Zhijie , Zhao Yunfeng , Xie Zemin 
Published: July 2008

AbstractA new type of polymeric curing agent (PCA) was synthesized to improve processing property, increase mechanical properties, and decrease volume shrinkage of silicone rubber. The PCA was prepared by co‐hydrolysis condensation of dimethyldiethoxysilane (DDS) and polyethoxysiloxane, then modified by hexamethylcyclotrisilazane (D3N). Commercial silica and tetraethoxysilane (TEOS) were used as controls simultaneously. The properties of polydimethylsiloxane (PDMS) composites were characterized by shear viscosity measurements, room temperature mass loss, linear volume shrinkage, stress‐strain tests, swelling behaviors and thermogravimetric analysis (TGA). PDMS composites using PCA show lower shear viscosity than those using commercial silica. Compared with the traditional PDMS/TEOS curing systems, PDMS/PCA curing systems behave relatively lower volume shrinkage, better reinforcement and thermal properties. In short, PCA acts as a good compromise in providing the best balance of processing property, volume shrinkage, mechanical properties and thermal stability in silicone rubber composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of high pressure gases on polymer‐solvent thermodynamic and transport behavior
Authors: Jones Adam T. , Danner Ronald P. , Duda J. Larry 
Published: July 2008

AbstractRemoval of residual solvent and monomers from a polymer through devolatilization can be the limiting step in production throughput. The process may be made more efficient by the addition of a cosolvent. In this work, the effects of two soluble gases, carbon dioxide, and ethylene, on the solubility and diffusivity of a number of solvents in poly(vinyl acetate) and poly(styrene) have been evaluated. The results indicate that in general the solubilities are reduced by the presence of the soluble gases and the diffusivity is significantly increased, with ethylene having the most pronounced effect. Larger solvent molecules benefit more by the presence of the added gas. The implications of this work are that replacement of noninteracting gases such as air or nitrogen with soluble gases can reduce solvent removal times and increase production rates. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Studying and increasing light stability of rotomolding grade of polyethylene
Authors: Feyz E. , Sharifi Sanjani N. , Shahraki H. , Ranji A. , Ala N. 
Published: July 2008

AbstractThis article covers the state‐of‐the‐art light stabilizer for rotational molding and the influence of synergistic effects between light and thermal stabilizers, which improve physical and mechanical properties. Different formulations of polyethylene (PE) with light stabilizer, thermal stabilizer, and acid scavenger have been produced in twin‐screw extruder. To study the light stability, sheets that produced by injection‐molding machine have been put in weather‐ometer instrument for 1000 h. After and before that, physical and mechanical properties have been evaluated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Cyclic extrusion of poly(butylene terephthalate)/organo‐montmorillonite nanocomposites: Thermal and mechanical retention properties
Authors: Chow Wen Shyang 
Published: July 2008

AbstractPoly(butylene terephthalate) (PBT) containing 3 wt % of organo‐montmorillonite (OMMT) was prepared using twin screw extrusion followed by injection molding. The effects of thermal cycles (two times extrusion followed by injection molding) were studied on both PBT and PBT/OMMT nanocomposites. The samples were characterized by using tensile tests, flexural tests, field‐emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and dynamic mechanical thermal analysis (DMTA). The intercalation of the OMMT silicate layers in the PBT was confirmed using XRD. Both tensile and flexural modulus of PBT was improved by addition of OMMT. DSC results revealed that OMMT improved the crystallinity of PBT. The percentage retention in tensile and flexural properties of PBT/OMMT(E2) intercalated nanocomposites (i.e. two times extrusion followed by injection molding) is more than 96%. The melting temperature, crystallization temperature, and degree of crystallinity of PBT/OMMT(E2) is comparable with PBT/OMMT(E1) (i.e. one time extrusion followed by injection molding). This indicates that PBT/OMMT intercalated nanocomposites exhibit good retention‐ability in mechanical and thermal properties after subjecting to two times twin‐screw extrusion followed by injection molding. From the TGA results, it was observed that the thermal stability (e.g. Tonset) of PBT was reduced by the addition of OMMT. However, the addition of OMMT assists in the char formation of PBT. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008