bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel method for estimating properties of attentional oscillators reveals an age-related decline in flexibility
Authors: Kaya Ece , Kotz Sonja A. , Henry Molly J.
Published: March 2024

Auditory tasks such as understanding speech and listening to music rely on the ability to track sound sequences and adjust attention based on the temporal cues they contain. An entrainment approach proposes that internal oscillatory mechanisms underlie the ability to synchronize with rhythms in the external world. Here, we aimed to understand the factors that facilitate and impede rhythm processing by investigating the interplay between the properties of external and internal rhythms. We focused on two key properties of an oscillator: its preferred rate, the default rate at which it oscillates in the absence of input, and flexibility, its ability to adapt to changes in rhythmic context. We hypothesized that flexibility would be diminished with advancing age. Experiment 1 was a two-session duration discrimination paradigm where we developed methods to estimate preferred rate and flexibility and assessed their reliability. Experiment 2 involved a shorter version of this paradigm and a paced tapping task with matched stimulus conditions, in addition to a
spontaneous motor tempo
(SMT) and two
preferred perceptual tempo
(PPT) tasks that measured motor and perceptual rate preferences, respectively. Preferred rates, estimated as the stimulus rates with the best performance, showed a harmonic relationship across sessions (Experiment 1) and were correlated with SMT (Experiment 2). Interestingly, estimates from motor tasks were slower than those from the perceptual task, and the degree of slowing was consistent for each individual. To challenge an individual’s oscillator flexibility, we maximized the differences in stimulus rates between consecutive trials in the duration discrimination and paced tapping tasks. As a result, performance in both tasks decreased, and performance on individual trials indicated a gravitation toward the stimulus rate presented in the preceding trial. Critically, flexibility, quantified as an individual’s ability to adapt to faster-than-previous rates, decreased with age. Overall, these findings show domain-specific rate preferences for the assumed oscillatory system underlying rhythm perception and production, and that this system loses its ability to flexibly adapt to changes in the external rhythmic context during ageing.
Machine learning and biological validation identify sphingolipids as potential mediators of paclitaxel-induced neuropathy in cancer patients
Authors: Lötsch Jörn , Gasimli Khayal , Malkusch Sebastian , Hahnefeld Lisa , Angioni Carlo , Schreiber Yannick , Trautmann Sandra , Wedel Saskia , Thomas Dominique , Ferreiros Bouzas Nerea , Brandts Christian H , Schnappauf Benjamin , Solbach Christine , Geisslinger Gerd , Sisignano Marco
Published: March 2024

Background:

Chemotherapy-induced peripheral neuropathy (CIPN) is a serious therapy-limiting side effect of commonly used anticancer drugs. Previous studies suggest that lipids may play a role in CIPN. Therefore, the present study aimed to identify the particular types of lipids that are regulated as a consequence of paclitaxel administration and may be associated with the occurrence of post-therapeutic neuropathy.

Methods:

High-resolution mass spectrometry lipidomics was applied to quantify d=255 different lipid mediators in the blood of n=31 patients drawn before and after paclitaxel therapy for breast cancer treatment. A variety of supervised statistical and machine-learning methods was applied to identify lipids that were regulated during paclitaxel therapy or differed among patients with and without post-therapeutic neuropathy.

Results:

Twenty-seven lipids were identified that carried relevant information to train machine learning algorithms to identify, in new cases, whether a blood sample was drawn before or after paclitaxel therapy with a median balanced accuracy of up to 90%. One of the top hits, sphinganine-1-phosphate (SA1P), was found to induce calcium transients in sensory neurons via the transient receptor potential vanilloid 1 (TRPV1) channel and sphingosine-1-phosphate receptors.SA1P also showed different blood concentrations between patients with and without neuropathy.

Conclusions:

Present findings suggest a role for sphinganine-1-phosphate in paclitaxel-induced biological changes associated with neuropathic side effects. The identified SA1P, through its receptors, may provide a potential drug target for co-therapy with paclitaxel to reduce one of its major and therapy-limiting side effects.

Funding:

This work was supported by the Deutsche Forschungsgemeinschaft (German Research Foundation, DFG, Grants SFB1039 A09 and Z01) and by the Fraunhofer Foundation Project: Neuropathic Pain as well as the Fraunhofer Cluster of Excellence for Immune-Mediated Diseases (CIMD). This work was also supported by the Leistungszentrum Innovative Therapeutics (TheraNova) funded by the Fraunhofer Society and the Hessian Ministry of Science and Arts. Jörn Lötsch was supported by the Deutsche Forschungsgemeinschaft (DFG LO 612/16-1).
Mycobacterium tuberculosis PhoP integrates stress response to intracellular survival by maintenance of cAMP level
Authors: Khan Hina , Paul Partha , Goar Harsh , Bamniya Bhanwar , Baid Navin , Sarkar Dibyendu
Published: March 2024

Survival of
M. tuberculosis
within the host macrophages requires the virulence regulator PhoP, but the underlying reason remains unknown. cAMP is one of the most widely used second messengers, which impacts on a wide range of cellular responses in microbial pathogens including
M. tuberculosis
. Herein, we hypothesized that intra-mycobacterial cAMP level could be controlled by the
phoP
locus since the major regulator plays a key role in bacterial responses against numerous stress conditions. A transcriptomic analysis reveals that PhoP functions as a represtsor of cAMP-specific phosphodiesterase (PDE) Rv0805, which hydrolytically degrades cAMP. In keeping with these results, we find specific recruitment of the regulator within the promoter region of
rv0805
PDE, and absence of
phoP
or ectopic expression of
rv0805
independently accounts for elevated PDE synthesis leading to depletion of intra-mycobacterial cAMP level. Thus, genetic manipulation to inactivate PhoP-
rv0805
-cAMP pathway decreases cAMP level, stress tolerance and intracellular survival of the bacilli.
Spatiotemporal dissection of the Golgi apparatus and the ER-Golgi intermediate compartment in budding yeast
Authors: Tojima Takuro , Suda Yasuyuki , Jin Natsuko , Kurokawa Kazuo , Nakano Akihiko
Published: March 2024

Cargo traffic through the Golgi apparatus is mediated by cisternal maturation, but it remains largely unclear how the cis-cisternae, the earliest Golgi sub-compartment, is generated and how the Golgi matures into the trans-Golgi network (TGN). Here, we use high-speed and high-resolution confocal microscopy to analyze the spatiotemporal dynamics of a diverse set of proteins that reside in and around the Golgi in budding yeast. We find many mobile punctate structures that harbor yeast counterparts of mammalian endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC) proteins, which we term ‘yeast ERGIC’. It occasionally exhibits approach and contact behavior toward the ER exit sites and gradually matures into the cis-Golgi. Upon treatment with the Golgi-disrupting agent brefeldin A, the ERGIC proteins form larger aggregates corresponding to the Golgi entry core compartment in plants, while cis- and medial-Golgi proteins are absorbed into the ER. We further analyze the dynamics of several late Golgi proteins to better understand the Golgi-TGN transition. Together with our previous studies, we demonstrate a detailed spatiotemporal profile of the entire cisternal maturation process from the ERGIC to the Golgi and further to the TGN.
ME3BP-7 is a targeted cytotoxic agent that rapidly kills pancreatic cancer cells expressing high levels of monocarboxylate transporter MCT1
Authors: Rincon-Torroella Jordina , Dal Molin Marco , Mog Brian , Han Gyuri , Watson Evangeline , Wyhs Nicolas , Ishiyama Shun , Ahmedna Taha , Minn Il , Azad Nilofer S , Bettegowda Chetan , Papadopoulos Nickolas , Kinzler Kenneth W , Zhou Shibin , Vogelstein Bert , Gabrielson Kathleen , Sur Surojit
Published: March 2024

Nearly 30% of Pancreatic ductal adenocarcinoma (PDAC)s exhibit a marked overexpression of Monocarboxylate Transporter 1 (MCT1) offering a unique opportunity for therapy. However, biochemical inhibitors of MCT1 have proven unsuccessful in clinical trials. In this study we present an alternative approach using 3-Bromopyruvate (3BP) to target MCT1 overexpressing PDACs. 3BP is a cytotoxic agent that is known to be transported into cells via MCT1, but its clinical usefulness has been hampered by difficulties in delivering the drug systemically. We describe here a novel microencapsulated formulation of 3BP (ME3BP-7), that is effective against a variety of PDAC cells in vitro and remains stable in serum. Furthermore, systemically administered ME3BP-7 significantly reduces pancreatic cancer growth and metastatic spread in multiple orthotopic models of pancreatic cancer with manageable toxicity. ME3BP-7 is, therefore, a prototype of a promising new drug, in which the targeting moiety and the cytotoxic moiety are both contained within the same single small molecule.
ME3BP-7 is a targeted cytotoxic agent that rapidly kills pancreatic cancer cells expressing high levels of monocarboxylate transporter MCT1
Authors: Rincon-Torroella Jordina , Molin Marco Dal , Mog Brian , Han Gyuri , Watson Evangeline , Wyhs Nicolas , Ishiyama Shun , Ahmedna Taha , Minn Il , Azad Nilofer S. , Bettegowda Chetan , Papadopoulos Nickolas , Kinzler Kenneth W. , Zhou Shibin , Vogelstein Bert , Gabrielson Kathleen , Sur Surojit
Published: March 2024

Nearly 30% of Pancreatic ductal adenocarcinoma (PDAC)s exhibit a marked overexpression of Monocarboxylate Transporter 1 (MCT1) offering a unique opportunity for therapy. However, biochemical inhibitors of MCT1 have proven unsuccessful in clinical trials. In this study we present an alternative approach using 3-Bromopyruvate (3BP) to target MCT1 overexpressing PDACs. 3BP is a cytotoxic agent that is known to be transported into cells via MCT1, but its clinical usefulness has been hampered by difficulties in delivering the drug systemically. We describe here a novel microencapsulated formulation of 3BP (ME3BP-7), that is effective against a variety of PDAC cells in vitro and remains stable in serum. Furthermore, systemically administered ME3BP-7 significantly reduces pancreatic cancer growth and metastatic spread in multiple orthotopic models of pancreatic cancer with manageable toxicity. ME3BP-7 is, therefore, a prototype of a promising new drug, in which the targeting moiety and the cytotoxic moiety are both contained within the same single small molecule.ME3BP-7 is a novel formulation of 3BP that resists serum degradation and rapidly kills pancreatic cancer cells expressing high levels of MCT1 with tolerable toxicity in mice.
Ligand response of guanidine-IV riboswitch at single-molecule level
Authors: Gao Lingzhi , Chen Dian , Liu Yu
Published: March 2024

Riboswitches represent a class of non-coding RNA that possess the unique ability to specifically bind ligands and, in response, regulate gene expression. A recent report unveiled a type of riboswitch, known as the guanidine-IV riboswitch, which responds to guanidine levels to regulate downstream genetic transcription. However, the precise molecular mechanism through which the riboswitch senses its target ligand and undergoes conformational changes remain elusive. This gap in understanding has impeded the potential applications of this riboswitch. To bridge this knowledge gap, our study investigated the conformational dynamics of the guanidine-IV riboswitch RNA upon ligand binding. We employed single-molecule fluorescence resonance energy transfer (smFRET) to dissect the behaviors of the aptamer, terminator, and full-length riboswitch. Our findings indicated that the aptamer portion exhibited higher sensitivity to guanidine compared to the terminator and full-length constructs. Additionally, we utilized Position-specific Labelling of RNA (PLOR) combined with smFRET to observe, at the single-nucleotide and single-molecule level, the structural transitions experienced by the guanidine-IV riboswitch during transcription. Notably, we discovered that the influence of guanidine on the riboswitch RNA’s conformations was significantly reduced after the transcription of 88 nucleotides. Furthermore, we proposed a folding model for the guanidine-IV riboswitch in the absence and presence of guanidine, thereby providing insights into its ligand-response mechanism.
Factores relevantes en la inscripción en cuidado infantil: Investigando el papel de la proximidad geográfica en centros de educación inicial chilenos
Authors:   , Rosales Ponce Constanza Solange
Published: March 2024

Se examina la relación entre la proximidad geográfica a los centros de cuidado infantil y la decisión de inscripción de los padres. Utilizando datos de la Encuesta Longitudinal de Primera Infancia (ELPI) de 2010 y 2012, se aplica un modelo bivariado logit para analizar esta relación. Se encuentra que la distancia al centro de cuidado infantil más cercano afecta significativamente la probabilidad de inscripción del niño. Estos hallazgos tienen implicaciones importantes para el diseño de políticas públicas destinadas a fomentar el uso de centros de cuidado infantil y mejorar los resultados de desarrollo infantil. Además, mediante el uso de variables instrumentales para abordar problemas de endogeneidad, se demuestra que la asistencia al jardín infantil a los 3 años tiene un impacto significativo en el desarrollo psicomotor y socioemocional de los niños, así como en la participación laboral de las madres y el estado de salud de los niños. En resumen, la investigación destaca la importancia de la accesibilidad geográfica a los centros de cuidado infantil y sugiere que las políticas públicas deben tener en cuenta este factor para maximizar su efectividad en el fomento del desarrollo infantil y la participación laboral femenina.
A Cross-sectional Study on the Pattern of Skull Fractures in Fatal Two-wheeler Road Traffic Accidents at a Tertiary Care Hospital in Northeastern India
Authors: Barman Nabajit , Thapa Gobil , Dowerah Swagata
Published: March 2024

Introduction: Death due to Road Traffic Accidents (RTA) is one of the leading causes of mortality and morbidity in a developing country like India. As there is a paucity of literature on the nature and type of injuries in RTAs in the locality of Upper Assam, a retrospective study on postmortem cases of fatal two-wheeler accidents was conducted to address the magnitude of the problem. Aim: To analyse different types of skull fractures and causes of death among two-wheeler RTAs at tertiary care Hospital in Northeast India. Materials and Methods: The present cross-sectional study was conducted in the mortuary of Assam Medical College, Dibrugarh, Assam, India, for a period of one year from August 2020 to July 2021. The records of all RTA cases involving twowheeler motorcycles brought for postmortem examination during this period were studied for parameters including age, gender distribution, cause of death, type of skull fracture, intracranial haemorrhage, and time of occurrence, and analysed using descriptive statistics. Results: There were 532 fatal RTA cases recorded, out of which 292 involved two-wheelers (54.89%). Males (87.67%) outnumbered females (12.33%). The most affected age group was between 21-30 years with a total of 98 cases (33.56%), followed by 31-40 years with 68 cases (23.29%). Skull fracture was present in 103 cases (35.27%). Fissured fracture was the most common type seen in 64 cases (62.14%) followed by depressed fracture in 19 (18.45%). The most common single bone fracture was of the Temporal bone in 44 cases (42.72%), followed by frontal bone in 18 (17.48%). Coma was the most common cause of death, seen in 214 cases (73.29%), followed by haemorrhagic shock in 42 (14.38%). Subdural Haemorrhage (SDH) alone was the most common intracranial haemorrhage found in 159 cases (74.30%), followed by Extradural Haemorrhage (EDH) alone in 7 cases (3.27%). Conclusion: Injuries to the skull and brain are the leading cause of death in RTAs. Adequate measures should be taken to prevent mortality and morbidity, achievable through strict enforcement of road safety measures, awareness among the people, and improving road infrastructure along with emergency medical services.
Performance of Cacao (Theobroma cacao L.) Varieties to Wood Ash and NPK Fertilizer on Flowering, Cherelle Wilt and Pod Yield
Authors: Babadele Famuwagun Idowu , Oyinkansola Ogunleye
Published: March 2024

Experiments were conducted to evaluate NPK fertilizer and wood-ash application on flowering, cherelle performance and pod yield of cacao (Theobobroma cacao L). Treatments includes NPK 15.15.15; NPK + wood-ash; sole wood-ash and control with five cacao varieties (TC1, TC2, TC3, TC4, and TC6) in a 4x5 factorial experiment with three replications. Data were measured on flowering, cherelle formation, and pod development. From the results, flowering, cherelle formation and pod development were significantly enhanced by application of NPK, sole wood-ash and their combinations over control plots. Application of wood-ash alone significantly enhanced flowering, cherelle formation and pod development in both seasons over other fertilizer treatments. However, cherelle wilt under sole application of wood-ash was significantly higher compared to sole NPK and NPK + wood-ash combinations.  Interaction effects of fertilizer and cacao varieties had significant positive effects on flower development and reduced cherelle wilt in both light and main crop seasons. Interactions of wood-ash and cacao varieties were found to significantly enhanced cherelle formation and pod development. The study concludes that NPK, NPK + wood-ash and sole wood-ash treatments significantly enhanced flowering, cherelle formation and pod development in cacao over the control. Also, cherelle with rate drop significantly with integration of NPK+wood-ash
Isolation, Biological Characterization, and Quality Inspection of Human Umbilical Cord-derived Mesenchymal Stem Cells for Clinical Research
Authors: Zuo Xia Lin , Dongcheng Wu , Yu Ding , Sa’ad Mohammad Auwal , Teng Samantha Lo Yin , Ravichandran Manickam , Ding Ke Xiang , Tham Seng Kong
Published: March 2024

Background: Human umbilical cord mesenchymal stem cells (hUCMSCs) represent a valuable and versatile cell type derived from the umbilical cord tissue of newborns. These cells exhibit diverse characteristics, including multipotent differentiation potential and low immunogenicity. hUCMSCs hold promise for clinical applications, yet concerns persist regarding their chromosomal stability. This study employs short tandem repeat (STR) analysis to assess genomic integrity. By focusing on chromosomal stability, the study aims to enhance confidence in the clinical viability of hUCMSCs, contributing to their safe and effective use in regenerative medicine. hUCMSCs were extracted from healthy newborn umbilical cords using tissue block adherence and enzyme digestion. The third generation of hUCMSCs undergoes biological characterization and quality checks, including examinations of cell morphology, viability, growth curves, surface markers, cell cycle, and multi-lineage differentiation potential. The result of the present study shows that hUCMSCs exhibit mesenchymal stem cell characteristics, with robust growth and high viability. Positive surface markers are expressed at rates exceeding 95%, while negative markers are ≤2%. Cell karyotyping analysis, STR spectrum identification, and chromosomal microarray analysis confirm genetic stability. Microbial testing shows the absence of contaminants, and immunological studies demonstrate the immunomodulatory capabilities of hUCMSCs. Specific residues, such as trypsin, were not detected. In conclusion, hUCMSCs produced under strict GLP and GMP conditions meet the quality guidelines for clinical application in various stem cell therapies. The findings support the clinical application of hUCMSCs in various medical contexts.
Corporate Governance and Performance of Listed Firms in Nigerian Exchange Group
Authors: Ayeni-Agbaje A. R. , Adebayo I. A. , Owoniya B. O.
Published: March 2024

The performance of listed firms in Nigeria is a topic of significant concern and interest among stakeholders, including investors, regulators, and policymakers. Despite the considerable growth and development of the Nigerian economy in recent years, some persistent challenges and issues affect the performance of listed firms, hindering their ability to achieve optimal results and contribute effectively to economic prosperity. There is a growing need to explore the relationship between corporate governance mechanisms and firm performance in Nigerian firms.The study adopted an ex-post facto research design, extracting secondary data from the annual reports of 153 companies listed on the Nigerian Exchange Group (NGX) that made up the study's population. Using a purposive sampling approach, 10 firms were chosen across different industries as the sample size. The scope spanned from 2013 to 2021, a period of nine years, and data underwent descriptive and inferential statistical analyses. The empirical investigations found that board size had a positive significant effect on return on assets, while the number of non-executive directors had a negative significant effect on return on assets. The overall results demonstrated that corporate governance had a significant effect on the firm performance. The findings suggest that companies adhering to robust corporate governance standards tend to excel across various performance metrics compared to those with weaker governance practices. This study recommends that Policymakers of Nigerian firms should consider optimizing board size to enhance performance, ensuring a balance between diversity and efficiency.
Influence of Organic Manures and Foliar Application of Arka Citrus Special on the Growth of Buddlings of Sweet Orange
Authors: Kalyan P. Pavan , Kumar T. Suresh , Sreenivas M. , Ramesh K. Venkata
Published: March 2024

In India, citrus fruits rank third in area and production after Mango and Banana. A study was conducted at the Horticultural Research Station (HRS) Konda Mallepally, Nalgonda district during Rabi, November 2022 - April 2023. The study aimed to test the effects of organic manures and foliar application of Arka Citrus Special on the growth of sweet orange cv. Sathgudi buddlings. The experiment included fourteen treatments with three replications in RBD. It comprised three types of organic manures (FYM, Vermicompost, Neem cake) and Arka Citrus Special (micronutrient formulation). The application of organic manures and micronutrients showed significant differences in plant height (cm), number of leaves, and leaf area (cm2). During 30, 60, 90 and 120 days of observations, the maximum plant height (26.99 cm), stem diameter (1.23 mm), number of leaves (26.00), girth of the plant (19.5 mm), leaf area (11.70 cm2), internodal length (0.260 cm), absolute growth rate (0.42 cm /day) and relative growth rate (0.10 cm /cm /day).
Studies on Effect of IBA Concentrations and Planting Times on Propagation of Different Varieties of Rose (Rosa hybrida Vill.)
Authors: Gupta Jagreeti , Brar Jagseer Singh , Dubey RK
Published: March 2024

The conventional method of rose propagation involves budding on one year old field established rootstock plants. For multiplication of plants, cutting is the simplest way of propagation of desirable rose varieties. There are relatively few varieties that develop roots, so exogenous application of growth promoters is essential. In order to study the effects of different concentrations of IBA (0, 500, 1000 and 1500 ppm) on rooting of different varieties (English Holiday, Eiffel Tower, Don Don, Confetti and Iceberg) of rose, during planting times viz., February, July, October and December, It was found that 500 ppm IBA resulted in maximum number of roots (15.66), number of leaves (22.33), the percentage of survival (50%), shoot length (13.23 cm), fresh weight of roots (4.80 g)  and stem (5.93 g), dry weight of roots (4.36 g) and stem (4.33 g) and took minimum days (13.00) for leaf bud initiation, whereas,the maximum root length (7.80 cm) was found in 1000 ppm IBA in Eiffel Tower variety and control treatment had the lowest effect on the different traits of rooting in rose cutting . Among different varieties, Eiffel Tower was found to be best in terms of different traits, whereas English Holiday and Confetti didn't respond to any of the planting times and treatments. Cuttings planted in February showed the highest effect on their evaluated traits with a significant difference with those planted in July and October, whereas in December planting time, zero survival rates was observed.
Prevalence and Forms of Intimate Partner Violence among People Living with HIV/AIDS in Sokoto State, Nigeria
Authors: Oche Oche Mansur , Kontagora Zainab Abdullahi , Ezenwoko Zainab Ahunna , Danmadami Abdulaziz Muhammad , Umaru Zainab , Garba Isah Hudu , Elijah Adenrele Temitope
Published: March 2024

Introduction: Intimate partner violence (IPV) is an aberrant behavior that occurs within an intimate relationship resulting in physical, sexual, and psychological harm to a partner. It transcends all strata of the society including socio-cultural groups, families and the community as a whole. Amongst people diagnosed with the Human Immuno-deficiency Virus (HIV), IPV could have adverse health consequences and this could have serious implications for disease progression, transmission and control. This study was therefore aimed at assessing the knowledge, prevalence and forms of IPV against people with HIV/AIDS in Sokoto metropolis, Nigeria.
Methods: A cross-sectional descriptive study design was used to recruit a total of 330 respondents which comprised adult male and female HIV/AIDS patients receiving comprehensive health care services in selected health facilities in Sokoto metropolis. Data on knowledge, prevalence and forms of IPV was elicited using a set of semi-structured interviewer- administered questionnaire downloaded into Open Data Kit (ODK).  Data collected was entered into and analyzed using SPSS statistical software version 25 with level of statistical significance set at p<0.05.
Results: More than two-thirds, 259 (78.5%) of the respondents were diagnosed with HIV within the last one to ten years with almost all, 323(97.9%) having good knowledge of IPV. Only 28 (8.5%) of the respondents experienced at least one form of IPV with more females (9.5%) compared to 4.5% of males experiencing IPV. The various forms of IPV experienced by the respondents included sexual (4.2%), physical (6.7%) and psychological (8.5%).    
Conclusion: Although almost all the respondents were knowledgeable about IPV, only a few of them experienced one form of IPV or the other. This has wider public health implications for interventions and underscores the need to initiate IPV screening among people living with HIV, improved awareness of IPV and supportive in care services and counseling aimed at better clinical outcomes amongst PLWHA.
Polymer–polymer mutual diffusion via rheology of coextruded multilayers
Authors: Zhao Rui , Macosko Christopher W.
Published: February 2007

The mutual diffusion coefficient of a pair of polyethylenes using coextruded multilayers has been measured. Two polyethylenes with different molecular weight were coextruded in 32 alternating layers in about 45 s of contact time. When the multilayer sample was remelted in a parallel plate rheometer, its apparent viscosity increased due to interdiffusion. By following the kinetics of the apparent viscosity increase, the mutual diffusion coefficient was measured. The theory of Kramer et al. (Polymer. 1984; 25:473‐480) was used to describe the mutual diffusion coefficient as a function of the chain mobility parameter, molecular weight, and concentration. The finite element method was used to solve the nonlinear interdiffusion problem to give a concentration profile in these multilayers. By fitting the apparent viscosity of the sample vs. time, the chain mobility parameter was found to be 4.5 × 1011 m/N s, and the range of the mutual diffusion coefficient for these two PE's was 10−12–10−14 m2/s at 200°C (depending on concentration). This is an easy and rapid method to measure the mutual diffusion coefficient for miscible polymers with different melt viscosities. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Preparation of porous structure in the system of PEEK/PPS/diphenyl ketone via thermally induced phase separation
Authors: Ding Huaiyu , Zhang Qiang , Tian Ye , Shi Yanqiao , Liu Biqian
Published: February 2007

The porous structure was prepared with polyether ether ketone (PEEK) and polyphenylene sulfide (PPS), which had excellent solvent resistance and thermal resistance as the mixed polymers, and diphenyl ketone as the diluent. The possibility of forming porous structure and the control of porous structure were investigated in the blended system. The effecting factors including the different weight ratios of PEEK/PPS and the total concentration of polymers on the porous structure are discussed, and the two‐step phase separation process brings forward the formation of membrane in this system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1523–1530, 2007
Properties of vulcanizates from blends of natural rubber and thioglycolic acid modified, epoxidized, low‐molecular‐weight natural rubber filled with carbonized rubber seed shell
Authors: Akinlabi A. K. , Okieimen F. E. , Okwu U. N. , Oladoja N. A.
Published: February 2007

Vulcanizates from blends of natural rubber and thioglycolic acid modified, epoxidized, low‐molecular‐weight natural rubber filled with mixtures of carbon black and carbonized rubber seed shell, with semiefficient sulfur vulcanization recipes, were critically investigated and characterized. The investigated properties were the processing and rheological properties (the cure rate, cure time, scorch time, total oscillating disc rheometry torque, and Mooney viscosity), physicomechanical and chemical properties, solvent resistance, solubility, and swelling properties. On the basis of the investigated properties, it was observed that the carbonized rubber seed shell acted as a plasticizer and not as a reinforcing filler such as carbon black. The replacement of carbon black with up to 20% carbonized rubber seed shell produced vulcanizates having processing advantages in time gain and energy consumption, with their physical, chemical, and mechanical properties around the acceptable level for natural rubber compounds but lower than the properties obtained for a 100% carbon black filled vulcanizate. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Removal of Hg2+ from aqueous solution using alginate gel containing chitosan
Authors: Chang Yu‐Hsin , Huang Chih‐Feng , Hsu Wei‐Ju , Chang Feng‐Chih
Published: February 2007

Glutaraldehyde‐crosslinked alginate gel containing chitosan (AGCC) used for the removal of Hg2+ ions from aqueous solutions. Three bead sizes were obtained and performed to study the uptake equilibrium and kinetics of Hg2+ by AGCC (ca. an hour). The adsorption capacity was found to be independent of adsorbent particle size indicating that sorption occurs in the whole AGCC bead. A high initial rate of Hg2+ uptake was followed by a slower uptake rate suggesting intraparticle diffusion as the rate‐limiting step. The rate of Hg2+ uptake increases with decreasing AGCC bead size. AGCC also enhanced the rate and the capacity of Hg2+ adsorption. The maximum Hg2+ adsorption capacity of AGCC was found 667 mg/g, which is over 20 times higher than that of alginate bead. Our results reveal the well‐distributed chitosan powders in the alginate gel bead and Hg2+ ions can reach inside the chitosan bead. It indicates the feasibility of using AGCC as metal adsorbent at low pH values, and allows the regeneration of adsorbent. Hg2+ ions adsorbed on AGCC bead were desorbed effectively about 95% by H2SO4 at the third cycle. The use of AGCC for the removal of Hg2+ ions from the waste streams appears to be promising. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis of amphiphilic poly(phthalazinone ether sulfone ketone)‐graft‐poly(ethylene glycol) graft copolymers via Williamson etherification
Authors: Zhu Li‐Ping , Zhu Bao‐Ku , Xu Li , Feng Yong‐Xiang , Xu You‐Yi
Published: February 2007

Amphiphilic graft copolymers consisting of poly(phthalazinone ether sulfone ketone) (PPESK) backbones and poly(ethylene glycol) (PEG) side chains were synthesized via reaction of chloromethylated PPESK (CMPPESK) with a sodium alkoxide of methoxyl PEG (PEG‐ ONa). The reactive precursor, CMPPESK, was prepared by the chloromethylation of PPESK with chloromethylether (CME) using concentrated H2SO4 as reaction medium. FTIR spectroscopy, 1H‐NMR and Solid‐state 13C CP‐MAS NMR analysis confirmed the covalent linking of PEG with PPESK backbones. The PEG content in the graft copolymers from 1H‐NMR analysis varied from 21.0 to 37.2 wt %, which was approximately in agreement with that calculated from TGA tests. The graft products have good solubility in many aprotic polar solvents and can be slightly swelled by water and ethanol, but water insoluble. Contact angle measurements revealed that the hydrophilicity of PPESK was significantly improved by the introduction of PEG graft chains, indicating the graft copolymer is a potential hydrophilic additive for PPESK membranes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007.
Properties of the enzyme electrode fabricated with a film of polythiophene derivative and its application to a glucose fuel cell
Authors: Kuwahara Takashi , Oshima Kenji , Shimomura Masato , Miyauchi Shinnosuke
Published: February 2007

A polymer electrode in the form of a thin film was prepared by electrochemical copolymerization of 3‐methylthiophene and thiophene‐3‐acetic acid. Glucose oxidase (GOx) was immobilized by covalent binding to the carboxyl groups on the electrode, and the GOx‐immobilized electrode (GOx‐electrode) was used as an anode in a glucose fuel cell. It was demonstrated by cyclic voltametry that in the presence of p‐benzoquinone (BQ), which was adopted as an electron mediator, the GOx‐electrode generated a significant glucose‐oxidation current depending on the concentrations of both glucose and BQ. A large surface area of the GOx‐electrode was considered to afford effective environment for the enzyme reaction and electron transfer. The fuel cell using the GOx‐electrode as an anode gave a power output of 42 μW/cm2‐anode at 30°C, when its anodic compartment contained 100 mM glucose and 10 mM BQ. The performance of the cell was influenced by the concentrations of glucose and BQ in the anodic compartment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Chemical modification of poplar wood with foaming polyurethane resins
Authors: Zhenhua Gao , Dong Li
Published: February 2007

This study was devoted to chemically modifying poplar wood with foaming polyurethane (PU) resin, which improved both dimension stability and mechanical property of wood. The controlled tests demonstrated the poplar wood treated with only solvent acetone had decreases of both dimension stability and mechanical property, while the wood modified with solution of polymetric methylenebis(phenylisocyanate) in acetone had an excellent improvement of dimension stability but a little strength loss. Seven foaming PU resins with NCO/OH mole ratio from 12 to 2.5 were used to chemically modified wood, of which the mole ratio 3.0 gave best balance between dimension stability and mechanical property. The 24‐h volumetric swelling coefficient (VSC24 h) and 24‐h water absorption coefficient (WAC24 h) of the modified wood reduced 34.29% and 57.60% and the modulus of rapture and modulus of elasticity improved 39.89% and 37.15%, respectively. The improvements of dimension stability were contributed to that of the hydrophilic hydroxyl groups in wood were blocked by isocyano groups and water movement was hindered by successive cued PU deposit on the surface of vessels. The improvements of mechanical property were owed to the reinforcement of foamed PU on the cell wall and void space of wood. Four morphologic models of foamed PU within wood were discovered by SEM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Sulfonated polyimide and poly (ethylene glycol) diacrylate based semi‐interpenetrating polymer network membranes for fuel cells
Authors: Lee Seokkyu , Jang Wonbong , Choi Seunghyuk , Tharanikkarasu Kannan , Shul Yonggun , Han Haksoo
Published: February 2007

Semi‐interpenetrating polymer network (semi‐IPN) membranes based on novel sulfonated polyimide (SPI) and poly (ethylene glycol) diacrylate (PEGDA) have been prepared for the fuel cell applications. SPI was synthesized from 1,4,5,8‐naphthalenetetracarboxylic dianhydride, 4,4′‐diaminobiphenyl 2,2′‐disulfonic acid, and 2‐bis [4‐(4‐aminophenoxy) phenyl] hexafluoropropane. PEGDA was polymerized in the presence of SPI to synthesize semi‐IPN membranes of different ionic contents. These membranes were characterized by determining, ion exchange capacity, water uptake, water stability, proton conductivity, and thermal stability. The proton conductivity of the membranes increased with increasing PEGDA content in the order of 10−1 S cm−1 at 90°C. These interpenetrating network membranes showed higher water stability than the pure acid polyimide membrane. This study shows that semi‐IPN SPI membranes based on PEGDA which gives hydrophilic group and structural stability can be available candidates comparable to Nafion® 117 over 70°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of the nature and degree of crosslinking on the Rose Bengal uptake by DVB‐, NNMBA‐, HDODA‐, and TTEGDA‐crosslinked aminopolyacrylamides
Authors: Gigimol M. G. , Mathew Beena
Published: February 2007

Polyacrylamides with 2–20 mol % divinyl benzene (DVB), N,N′‐methylene‐bisacrylamide (NNMBA), 1,6‐hexanediol diacrylate (HDODA), and tetraethyleneglycol diacrylate (TTEGDA) crosslinking and without crosslinking were prepared by free radical solution polymerization. Amino functions were incorporated into these polymers by transamidation with excess ethylenediamine. The dye uptake of nonprotonated and protonated aminopolyacrylamides was followed by batch equilibration method towards Rose Bengal (RB), Methyl Orange (MO), Methyl Red (MR), and Methylene Blue (MB). RB uptake by the polyacrylamide‐supported systems is higher than other dyes. Generally the dye uptake by the protonated systems is higher than the nonprotonated systems. To optimize the conditions of dye uptake, the effect of the concentration of RB solutions, temperature, and pH were followed. Kinetic studies showed that the uptake of RB by both nonprotonated and protonated crosslinked aminopolyacrylamides is a phase boundary process followed by three‐dimensional diffusion. The extent of RB uptake by the various systems depends on the nature and degree of crosslinking, and the relative rigidity/flexibility ofthe polyacrylamide support. Thus, the dye uptake followed the order: linear > NNMBA‐ > DVB‐ > TTEGDA‐ > HDODA‐crosslinked system. The dye uptake followed the same trend as the variation of amino capacity with degree of crosslinking in the respective crosslinked system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Generation and characterization of compositional gradient structure in the biodegradable chitosan/poly(ethylene oxide) blend
Authors: Osugi Nobuyuki , Dong Tungalag , Hexig Bayar , Inoue Yoshio
Published: February 2007

Bio‐inspired gradient materials based on the biodegradable polymer blend are expected to be indispensable to the new approaches for biomedical applications. In this study, multi‐step casting self‐organization on the aluminum surface are used to control the compositional distribution in the blend films of biodegradable chitosan and poly(ethylene oxide). By this way, three kinds of compositional gradient, i.e., pseudobilayer (PG), gradient (G) and semigradient (SG) blend films, along the film thickness were prepared. Their compositional morphologies were evaluated by means of ATR‐FTIR and FTIR mapping measurements. In addition, the moisture absorption behavior and the mechanical properties of the gradient film were characterized with referring their gradient morphologies. It is found that the compositional G films has better mechanical properties compared with those of the PG and SG films in both the dry and wet states. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Age‐ and site‐specific decline in insulin‐like growth factor‐I receptor expression is correlated with differential growth plate activity in the mouse hindlimb
Authors: Serrat Maria A. , Lovejoy C. Owen , King Donna
Published: February 2007

The proximal and distal growth plates of the principal long bones do not contribute equally to longitudinal growth. Most forelimb elongation occurs at the shoulder and wrist, while most hindlimb growth occurs at the knee. This study examined whether insulin‐like growth factor‐I (IGF‐I), a potent growth regulator, could underlie this variation via differential receptor expression. The spatiotemporal distribution of the IGF‐I receptor (IGF‐IR) was mapped in hindlimb growth plates (overall and within regional zones) from immature mice using immunohistochemistry. Growth activity was assessed by size/morphology of the growth plate and proliferating cell nuclear antigen (PCNA) expression. Both IGF‐IR and PCNA staining declined considerably with age in the proximal femur and distal tibia (hip and ankle), but expression remained high in the more active distal femur and proximal tibia (knee) throughout growth. Growth plate size decreased with age in all sites, but the absolute and relative decline in IGF‐IR in the hips and ankles of older mice indicated a site‐specific loss of IGF‐I sensitivity in these less active regions. These results suggest that regulation of the IGF‐IR may at least partially mediate differential long bone growth, thereby providing a local mechanism for altering skeletal proportions absent modification of systemic hormone levels. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.
Improvement of Sjögren's syndrome after two infusions of rituximab (anti‐CD20)
Authors: Devauchelle‐Pensec Valérie , Pennec Yvon , Morvan Johanne , Pers Jacques‐Olivier , Daridon Capucine , Jousse‐Joulin Sandrine , Roudaut Anne , Jamin Christophe , Renaudineau Yves , Roué Isabelle Quintin , Cochener Béatrice , Youinou Pierre , Saraux Alain
Published: February 2007

Objective

There is evidence to support a dominant role for B cells in the pathophysiology of primary Sjögren's syndrome (SS). Therefore, we evaluated the safety and efficacy of anti‐CD20 monoclonal antibody.

Methods

Sixteen patients who met the new American‐European Consensus Group criteria for primary SS and scored >50 on at least 2 of 4 visual analog scales (VAS; 100 mm) evaluating global disease, pain, fatigue, and global dryness received infusions of low‐dose rituximab (375 mg/m2) at weeks 0 and 1 without steroid premedication.

Results

Slow rituximab infusions (100 mg/hour) were well tolerated, with only 1 patient experiencing serum sickness–like disease. There was a dramatic reduction in B cells of the blood and salivary gland (SG). At week 12, VAS scores with respect to fatigue and dryness (P < 0.05), tender point count (P < 0.035), and quality of life as evaluated by the Short Form 36 questionnaire (SF‐36; P < 0.001) were significantly improved. At week 36, significant improvements were noted in the 4 VAS scores (P < 0.05), tender joint count (P = 0.017), tender point count (P = 0.027), and SF‐36 (P < 0.03). Pulmonary manifestations were ameliorated in 1 patient. Patients with improvements on at least 3 of the 4 VAS scores at any visit (n = 11) had a shorter disease duration than the other patients (n = 5; mean ± SD duration 3.8 ± 5.4 versus 30.1 ± 29.5 years; P = 0.02).

Conclusion

Low‐dose rituximab infusions were well tolerated without the benefit of steroids. Infusions induced a rapid depletion of B cells in the blood and SG and could improve primary SS. Controlled studies are needed.
Purification and characterization of the enantioselective nitrile hydratase from Rhodococcus sp. AJ270
Authors: Song Liya , Wang Meixiang , Yang Xiuqing , Qian Shijun
Published: February 2007

Nitrile hydratase (NHase, EC 4.2.1.84) from Rhodococcus sp. AJ270 was purified with 23.96% yield after sonication, ammonium sulfate fractionation, ion exchange, hydrophobic and gel‐filtration column chromatography. The enzyme showed intriguing characteristics: it hydrated not only aliphatic and heterocyclic nitriles but also aromatic ones. Some substrates were also hydrated enantioselectively to the corresponding amides. The enantiomeric excess (ee) value of the enzyme hydrating trans‐2,2‐dimethyl‐3‐phenylcyclopropanecarbonitrile was 84.7. The enzyme is composed of two subunits: an α subunit and β subunit of 22 975 Da and 23 493 Da, respectively. The optimal temperature and pH for the catalytic reaction of the enzyme was 25°C and pH 7.6. The enzyme activity of the purified NHase was strongly inhibited by some oxidizing agents and heavy metals.
Bronchiectasis: A study of the pathology of sixteen surgical lobectomies for bronchiectasis
Authors: Robinson W L
Published: February 2007

The problem of bronchieetasis, its etiology, pathology, and treatment, has held the interest and attention of clinician and pathologist alike for many years. Laennee1 (1826) was probably the first to refer to this condition. The next important contribution to the subject was that of Corrigan2 (1838), who, in a paper on cirrhosis of the lung, reported four cases. He considered the disease to be primarily a fibrosis of the lung with dilatation of the bronchi produced by traction of the scar tissue.
Spontaneous rupture of extensor pollicis longus tendon associated with colles's fracture
Authors: Moore Thomas
Published: February 2007

The object of this paper is to report three cases of spontaneous rupture of the extensor pollicis longus tendon associated with Colles's fracture.
Randomized comparison of the neuroendocrine response to laparoscopic cholecystectomy using either conventional or abdominal wall lift techniques
Authors: Koivusalo A-M , Kellokumpu I , Scheinin M , Tikkanen I , Halme L , Lindgren L
Published: February 2007

Increases in plasma renin activity and noradrenaline concentration occur in response to carbon dioxide insufflation during laparoscopic cholecystectomy. In a randomized study the conventional carbon dioxide pneumoperitoneum was compared with the abdominal wall lift method for laparoscopic cholecystectomy, with special reference to neuroendocrine changes and renal function. The total mean(s.d.) volume of carbon dioxide insufflated was 42(23) litres with the conventional method and 9(7) litres with abdominal wall lift (P< 0·001). Mean(s.d.) intra-abdominal pressure after 15 min of insufflation was 11(2) and 3(9) mmHg respectively (P<0·01). In the conventional group mean(s.d.) plasma renin activity increased slightly from 5·5(2·1) to 6·1(2·0) ng ml−1 during the first 55 min of laparoscopic cholecystectomy. In the abdominal wall lift group plasma renin activity decreased from 5·3(2·7) to 3·8(0·9) ng ml−1 (P<0·01 between the groups). Plasma antidiuretic hormone concentration increased similarly in both groups. Diuresis was significantly less with conventional pneumoperitoneum during the first 35 min of the operation compared with the abdominal wall lift method (P< 0·001). There were significant increases in plasma noradrenaline concentration in both groups (P< 0·001), but the increase was slightly higher in the conventional group during the first 15 min of insufflation. The abdominal wall lift method with minimal carbon dioxide insufflation was associated with smaller neuroendocrine responses and better preservation of renal function compared with conventional carbon dioxide pneumoperitoneum.