bluuebunny/crossref_metadata_2025 huggingface dataset:
Women's health: the unfinished agenda
Authors: Tinker Anne
Published: July 2002

Improving women's health and nutrition could save millions of women in developing countries from needless suffering or premature death. Cost‐effective health interventions exist to prevent this loss of lives. Complications of pregnancy and childbirth are the leading cause of death and disability among women of reproductive age in developing countries. Malnutrition is a major contributory factor to women's poor health and preventable mortality. Domestic violence, sexual abuse, and female genital mutilation carry a heavy physical and mental toll, as well as constitute an intolerable violation of human rights. Women's health is influenced by complex biological, social, and cultural factors that are highly interrelated. Significant progress can be achieved by strengthening and expanding an essential package of health services for women, improving the policy environment, and promoting more positive attitudes and behavior towards women's health.
Factors affecting postoperative pregnancy rate after endoscopic management of large endometriomata
Authors: Milingos S , Kallipolitis G , Loutradis D , Liapi A , Drakakis P , Antsaklis A , Michalas S
Published: July 2002

Objective: To identify factors influencing postoperative pregnancy rate in women with extensive endometriosis and large endometriomata as the only identified cause of infertility that were treated by laparoscopy. Method: Sixty‐four infertile patients with endometriomata (≥3 cm) and no other apparent cause of infertility. The latter were removed by operative laparoscopy. Life table calculations, the Student's t‐test and the χ2 test were used where appropriate. Result: Thirty‐four patients (53%) became pregnant during the 2‐year follow‐up period. A significantly increased pregnancy rate was found for the first year compared to the second (76 vs. 24%). The existence of adhesions affected adversely the outcome of the operation only as far as early achievement of pregnancy is considered. The number and size of endometriomata and the existence of peritoneal implants have not been found to affect pregnancy rates. The severity of the disease did not affect pregnancy rate, but in the cases with moderate disease most of the pregnancies were achieved during the first postoperative year. The duration of infertility was significantly associated only at the 10% level with decreased pregnancy rates. Conclusion: Extensive endometriosis with large endometriomata can be safely and effectively treated with laparoscopy using the traditional laparoscopic tools providing the infertile patient with a high chance to conceive in a relatively short period of time postoperatively.
An evaluation of the relationship between management practices and computer aided design technology
Authors: Malhotra Manoj K , Heine Michelle L , Grover Varun
Published: July 2002

Technology has been the engine of growth for the United States economy over the last decade, and it is reasonable to expect that appropriate selection and management of technology within the firm would continue to be highly critical to its success well into the future. Operations managers constantly struggle to seek answers to the right set of managerial actions that can be used to leverage technology for process effectiveness. This study takes a step in that direction by empirically examining the management of computer aided design (CAD) technology and outcomes of the product design process within manufacturing firms. In particular, the level of functionality and sophistication of the CAD system are examined with respect to the use of several structural and infrastructural management levers such as the degree of a firm’s formalization and decentralization, the extent of the use of teams, the extent of training of CAD designers, and the equity of the incentives within the product design process. The influence of these management levers upon the CAD system performance is analyzed through the use of moderated regression analysis conducted on a cross‐sectional data of 143 firms representing the vehicular industry in the USA. Our findings indicate that CAD functionality and sophistication are positively related to product design quality, flexibility, and overall performance. The impact of management levers on this relationship is a mixed one. Decentralization has no impact on the CAD technology–performance relationship, formalization has some positive effects, and the use of teams is helpful only in moderating the influence of sophistication on overall performance. Equity of incentives enhances design quality, while training is very important in improving performance across the board. In general, sophisticated “state of the art” CAD systems require much more proactive management than highly functional ones. Recommendations emerging from this study hopefully provide insights into a better management of not only CAD systems, but other process level technologies as well that are relevant to firms in the manufacturing sector. We also discuss implications of technology management provided by this research for creating leading edge enterprises.
Medroxyprogesterone acetate alone or synergistic with chemotherapy suppresses colony formation and DNA synthesis in C6 glioma in vitro
Authors: Altinoz Meric A. , Bilir Ayhan , Ozar Engin , Onar Funda Durmaz , Sav Aydin
Published: July 2002

We have studied the effects of medroxyprogesterone acetate (MPA) on C6 glioma growth in vitro in order to prove the hypothesis that it could arrest growth and induce drug sensitisation in a glial tumour as it does in breast cancer cells. Plating, thymidine‐labelling index, ultra‐structure, and soft agar colony growth were determined after incubation with MPA, and/or cisplatin, procarbazine and methotrexate (MTX). MPA (1 μg/ml) reduced the thymidine‐labelling index by 41 and 73% at 48 and 96 h, respectively, and decreased colony growth by 61%. Soft agar colony inhibition by MPA was almost as potent as MTX (0.3 μg/ml), but the latter drug showed very high cytotoxicity. Electron microscopy revealed that in medroxyprogesterone treated cells myeloid bodies developed, but MTX treatment caused mainly necrosis. Medroxyprogesterone increased procarbazine and cisplatin‐induced colony growth and S‐phase inhibition, but reduced MTX‐induced thymidine‐labelling inhibition. In conclusion, progesterone may inhibit growth and sensitize to drugs.
The treatment of anxiety disorders: a legacy of William Sargant
Authors: Gelder MG
Published: July 2002

In 1962 William Sargant and his colleagues described the therapeutic value of phenelzine, a monoamine oxidase inhibitor (MAOI), in chronic anxiety disorders and in the same year Klein and Fink reported the treatment of similar conditions with imipramine, a tricyclic antidepressant. Subsequent research has confirmed these findings and demonstrated the range of similar drugs that are effective in anxiety disorders. At the time of these original observations about the drug treatment of anxiety, there were no psychological treatments of proven value but in the intervening years much progress has been made in developing behavioural and cognitive procedures. The progress in determining the mode of action of these pharmacological and psychological treatments is reviewed and the implications of the findings are considered in relation to research into the causes of the anxiety disorders and to the treatment of patients.
Delayed onset of action of antidepressant drugs? Survey of recent results
Authors: Stassen H.H. , Angst J , Delini-Stula A
Published: July 2002

The onset of action of antidepressant drugs was investigated on the basis of two independent multicenter, double-blind efficacy studies comparing amitriptyline (n= 120), oxaprotiline (n= 120), imipramine (n= 506) and moclobemide (n= 580) with placebo (n= 189 + 191). The samples consisted of in- and outpatients diagnosed, according to Diagnostic and Statistical Manual (DSM)-III criteria, as suffering from major depressive disorder. Measures of efficacy criteria were the Hamilton Rating Scale for Depression (HAM-D), the Hamilton Rating Scale for Anxiety (HAM-A) and the Zung Self-Rating Depression scale. By using the Sustained Relative Improvement (SRI) criterion, onset of action was determined in each individual patient as that time point in the 30 day observation period at which a 20% baseline score reduction was achieved without subsequent deterioration. Analogously, a response to treatment was defined as a 50% baseline score reduction. As expected, highly significant differences between active drugs and placebo were found with respect to the total number of improvers and responders. Significant differences between treatment modalities surfaced in the percentage rate as well as the time distribution of premature withdrawals. Yet, unexpectedly, among improvers, the time spans to onset of improvement were found to be independent of treatment modality as indicated by virtually identical cumulative percentages of improvers throughout the whole observation period. The picture was essentially the same for the HAM-A and Zung assessments, except for a significant time lag between observer- and self-ratings. In particular, our analyses revealed no evidence for a delayed onset of action under various antidepressants with large biochemical and pharmacological differences in comparison to placebo. Moreover, the early onset of improvement was highly predictive of later outcome: on average, 70% of the patients showing improvement within the first 14 days became responders. Applying survival-analytical methods, we found that differences between active treatments and placebo emerged within the first 5 days and reached a point of maximum distinction around day 14. After this time point, differences between treatment modalities remained constant until the end of the observation period. According to our data, 20–25% of the patients were, on average, ‘true’ drug responders, thus suggesting that the therapeutic qualities of antidepressants do not lie in the suppression of symptoms, but rather are related to their ability to elicit and maintain certain conditions which allow recovery in a subgroup of patients who would otherwise remain non-responders.
Field and simulation‐based assessment of vetivergrass bioenergy feedstock production potential in Texas
Authors: Meki Manyowa N. , Kiniry James R. , Worqlul Abeyou W. , Kim SuMin , Williams Amber S. , Osorio Javier M. , Reilley John
Published: April 2020

Vetivergrass [Chrysopogon zizanioides (L.) Roberty] is a multi‐purpose crop that has an untapped potential for biofuel production. We conducted a field study at Temple, TX, to determine plant growth characteristics that make vetivergrass an ideal candidate bioenergy feedstock crop. Overall, the high biomass yield (avg. 18.4 ± 0.7 Mg ha−1) can be attributed to the high leaf area index (LAI, avg. 12.7 ± 2.5) and crop growth rates that ranged from 2.7 ± 0.1 to 15.7 ± 0.1 g m−2 d−1. Plant tissue N and P concentrations ranged from 0.59–1.66% and 0.06–0.15%, respectively. Surprisingly, the radiation use efficiency (RUE, avg. 2.2 ± 0.1 g MJ−1) was not high relative to other highly productive grasses. Biomass yield was highly correlated to plant height (avg. 2.1 ± 0.1 m) and LAI (Pearson, r = 0.96 and 0.77, respectively). Data from the field experiment provided plant coefficients that were used to develop an Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) vetivergrass model to assess dryland and irrigated interannual and spatial biomass yields across Texas. ALMANAC simulated dryland and irrigated yields ranged from 0.8–39.3 (avg. 17.2) Mg ha−1 and 9.1–47.0 (avg. 25.4) Mg ha−1, respectively. There was huge spatial variation in dryland and irrigated yields, with CV values of 20 and 15%, respectively. Similarly, dryland and irrigated inter‐annual yields respectively had CV values of 25 and 17%. State‐wide simulation model assessments complement field studies, and furthermore allow bioenergy companies and investors to better estimate biofuel feedstock potential for new crops such as vetivergrass.
Cover crop productivity and subsequent soybean yield in the western Corn Belt
Authors: Koehler‐Cole Katja , Elmore Roger W. , Blanco‐Canqui Humberto , Francis Charles A. , Shapiro Charles A. , Proctor Christopher A. , Ruis Sabrina J. , Heeren Derek M. , Irmak Suat , Ferguson Richard B.
Published: April 2020

Cover crops (CC) in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations may prevent N loss and provide other ecosystem services but CC productivity in the western Corn Belt is limited by the short growing season. Our objective was to assess CC treatment and planting practice effects on CC biomass, spring soil nitrate concentrations, and soybean yield at two rainfed sites in eastern and one irrigated site in south‐central Nebraska over 4 yr. Cover crop treatments (cereal rye [Secale cereale L.] [RYE] and a mix of rye, legume, and brassica species [MIX]) were planted by broadcast interseeding into corn stands in September (pre‐harvest broadcast) or drilling after corn harvest (post‐harvest drilled) and terminated 2 wk before planting soybean. Cover crop biomass and N uptake varied between years, but generally at the eastern sites, pre‐harvest broadcasting produced more biomass than post‐harvest drilling (1.64 and 0.79 Mg ha−1, respectively) and had greater N uptake (37 and 24 kg ha−1, respectively). At the south‐central site, post‐harvest drilling produced more than pre‐harvest broadcasting (1.44 and 1.20 Mg ha−1, respectively). RYE had more biomass than MIX (1.41 and 1.09 Mg ha−1, respectively), but the same N uptake. Soil nitrate reductions after CC were small. In 3 of 12 site‐years, soybean yielded less after pre‐harvest CC. Yield reductions were not correlated to CC biomass, but were likely due to greater weed pressure. High CC productivity is necessary for high N uptake, and requires site‐specific selection of planting practice and CC treatments.
The aging common marmoset's immune system: From junior to senior
Authors: Mietsch Matthias , Paqué Kristina , Drummer Charis , Stahl‐Hennig Christiane , Roshani Berit
Published: April 2020

The social, health, and economic challenges of a steadily increasing aging population demand the use of appropriate translational animal models to address questions like healthy aging, vaccination strategies, or potential interventions during the aging process. Due to their genetic proximity to humans, especially nonhuman primates (NHPs) with a relatively short generation period compared to humans, qualify as excellent animal models for these purposes. The use of common marmosets (Callithrix jacchus) in gerontology research steadily increased over the last decades, yet important information about their aging parameters are still missing. We therefore aimed to characterize their aging immune system by comprehensive flow cytometric phenotyping of blood immune cells from juvenile, adult, aging, and geriatric animals. Aged and geriatric animals displayed clear signs of immunosenescence. A decline in CD4/CD8 ratio, increased expression of HLA‐DR and PD‐1, higher frequencies of CD95+ memory cells, alterations in cytokine secretion, and a decline in the proliferative capacity proved T cell senescence in aging marmosets. Also, the B cell compartment was affected by age‐related changes: while overall B cell numbers remained stable with advancing age, expression of the activation marker CD80 increased and immunoglobulin M expression decreased. Interestingly, marmoset B cell memory subset distribution rather mirrored the human situation than that of other NHP. CD21+ CD27− naïve B cell frequencies decreased while those of CD21− CD27− tissue memory B cells increased with age. Furthermore, frequencies and numbers of NK cells as part of the innate immune system declined with advancing age.

Thus, the observed immunological changes in common marmosets over their life span revealed several similarities to age‐related changes in humans and encourages further studies to strengthen the common marmoset as a potential aging model.
Spectrally Combined Encoding for Profiling Heterogeneous Circulating Tumor Cells Using a Multifunctional Nanosphere‐Mediated Microfluidic Platform
Authors: Wu Ling‐Ling , Zhang Zhi‐Ling , Tang Man , Zhu Dong‐Liang , Dong Xiao‐Juan , Hu Jiao , Qi Chu‐Bo , Tang Hong‐Wu , Pang Dai‐Wen
Published: April 2020

Comprehensive phenotypic profiling of heterogeneous circulating tumor cells (CTCs) at single‐cell resolution has great importance for cancer management. Herein, a novel spectrally combined encoding (SCE) strategy was proposed for multiplex biomarker profiling of single CTCs using a multifunctional nanosphere‐mediated microfluidic platform. Different cellular biomarkers uniquely labeled by multifunctional nanosphere barcodes, possessing identical magnetic tags and distinct optical signatures, enabled isolation of heterogeneous CTCs with over 91.6 % efficiency and in situ SCE of phenotypes. By further trapping individual CTCs in ordered microstructures on chip, composite single‐cell spectral signatures were conveniently and efficiently obtained, allowing reliable spectral‐readout for multiplex biomarker profiling. This SCE strategy exhibited great potential in multiplex profiling of heterogeneous CTC phenotypes, offering new avenues for cancer study and precise medicine.
Design of electrical conductive poly(lactic acid)/carbon black composites by induced particle aggregation
Authors: Kim Ji Hwan , Hong Joung Sook , Ahn Kyung Hyun
Published: April 2020

The electrical conductivity of ternary composites composed of a biopolymer blend with conductive particles (carbon black [CB]) is induced by the control of particle dispersion in the dispersed phase. If the CB particles have higher chemical affinity for the secondary phase (poly(caprolactone) [PCL]]) than the matrix (poly(lactic acid) [PLA]), especially as the concentration of the PCL phase decreases significantly to 4 wt%, the PCL phase induces the aggregation of CB particles beyond the selective localization, resulting in a shift of the particle percolation threshold to a lower concentration of particles (2.44 wt% CB). Moreover, the mixing ratio between the CB and the PCL phase significantly affects the formation of percolation of particles. When the mixing ratio of CB to PCL is equivalent (1:1), the ternary composite shows high electrical DC conductivity above 1 S/m with 10 wt% CB. The addition of a small amount of PCL induces the formation of particle aggregates with a high aspect ratio, providing more electron transfer pathways due to the multiple points of contact between the particle aggregates (power law scaling exponent of the composites ~2.14). Meanwhile, a binary composite (PLA/CB) never reaches high electrical conductivity of 1 S/m and even requires a greater concentration of CB (13 wt% CB for 10−3 S/m) to accomplish electron transfer because of the small aspect ratio of randomly dispersed particle aggregates (power law scaling exponent ~3.20).
Locoregional recurrences after transanal total mesorectal excision of rectal cancer during implementation
Authors: Oostendorp S E , Belgers H J , Bootsma B T , Hol J C , Belt E J T H , Bleeker W , Den Boer F C , Demirkiran A , Dunker M S , Fabry H F J , Graaf E J R , Knol J J , Oosterling S J , Slooter G D , Sonneveld D J A , Talsma A K , Van Westreenen H L , Kusters M , Hompes R , Bonjer H J , Sietses C , Tuynman J B
Published: April 2020

Background

Transanal total mesorectal excision (TaTME) has been proposed as an approach in patients with mid and low rectal cancer. The TaTME procedure has been introduced in the Netherlands in a structured training pathway, including proctoring. This study evaluated the local recurrence rate during the implementation phase of TaTME.

Methods

Oncological outcomes of the first ten TaTME procedures in each of 12 participating centres were collected as part of an external audit of procedure implementation. Data collected from a cohort of patients treated over a prolonged period in four centres were also collected to analyse learning curve effects. The primary outcome was the presence of locoregional recurrence.

Results

The implementation cohort of 120 patients had a median follow up of 21·9 months. Short-term outcomes included a positive circumferential resection margin rate of 5·0 per cent and anastomotic leakage rate of 17 per cent. The overall local recurrence rate in the implementation cohort was 10·0 per cent (12 of 120), with a mean(s.d.) interval to recurrence of 15·2(7·0) months. Multifocal local recurrence was present in eight of 12 patients. In the prolonged cohort (266 patients), the overall recurrence rate was 5·6 per cent (4·0 per cent after excluding the first 10 procedures at each centre).

Conclusion

TaTME was associated with a multifocal local recurrence rate that may be related to suboptimal execution rather than the technique itself. Prolonged proctoring, optimization of the technique to avoid spillage, and quality control is recommended.
Evaluation of exosome loading characteristics in their purification via a glycerol‐assisted hydrophobic interaction chromatography method on a polyester, capillary‐channeled polymer fiber phase
Authors: Huang Sisi , Wang Lei , Bruce Terri F. , Marcus R. Kenneth
Published: April 2020

Exosomes are membrane‐secreted vesicles, with sizes ranging from 30 to 150 nm, which play key roles in intercellular communication. There is intense interest in developing methods to isolate and quantify exosomes toward clinical diagnostics, fundamental studies of intercellular processes, and use of exosomes as delivery vehicles for therapeutic agents. Current methods for exosomes isolation and quantification are time consuming and have operational high costs; few combine isolation and quantification into a singular operation unit. This report describes the use of hydrophobic interaction chromatography on a polyester capillary‐channeled polymer fiber column, employing a step gradient for exosome elution, including use of glycerol as a solvent modifier. The entire procedure is completed in 8 min, while maintaining the structural integrity and biological activity of the isolated exosomes. Electron microscopy was used to verify the size and structural fidelity of single exosomes. Absorbance response curves for a commercial exosome sample were used for exosome quantification in the chromatographic separations. In order to determine the dynamic loading capacity for exosomes, different volumes of Dictyostelium discoideum cell culture milieu supernatant were loaded at different column lengths (5–30 cm) and loading flow rates (0.2–0.5 ml/min). A loading capacity of 5.4 × 1012 exosomes derived from D. discoideum milieu was obtained on a 0.8 × 300 mm column; yielding recoveries of over 80%. It is believed that this isolation and purification strategy holds many advantages toward the use of exosomes across a wide breadth of medical and biotechnology applications.
Serum levels of 25‐hydroxy‐vitamin D in patients with oral squamous cell carcinoma: Making a case for chemoprevention
Authors: Udeabor Samuel E. , Albejadi Abdullah M. , Al‐Shehri Waleed A. K. , Onwuka Chidozie I. , Al‐Fathani Saeed Y. , Al Nazeh Abdullah A. , Aldhahri Saleh F. , Alshahrani Faleh A.
Published: April 2020

Objectives

Serum level of vitamin D has been used as a predictor for cancer development. We intend to measure the baseline vitamin D level in patients with oral squamous cell carcinoma (OSCC) and to compare same with non‐cancer controls to determine any association.

Materials and methods

Patients with OSCC presenting to our clinics were included in this study. Their baseline serum vitamin D levels were measured prior to cancer treatment after obtaining their consents. These patients were then matched with at least 2 cancer‐free subjects to serve as controls and whose serum vitamin D levels were also measured. The serum vitamin D levels obtained for the two groups were then categorized into normal (>35 ng/ml), mild deficiency (25–35 ng/ml), moderate deficiency (12.5–25 ng/ml), and severe deficiency (<12.5 ng/ml). The data were analyzed statistically and the two groups compared.

Results

A total of 51 patients with OSCC (Male 22 [43%] and female 29 [57%]) and 113 cancer‐free controls (Male 36 [31.86%] and female 77 [68.14%]) were included in the study. The commonest site for OSCC was the tongue, accounting for 45% of the cancer cases. Mean age for cancer patients was 59.33 years ±12.54 and 49.24 years ±15.79 for the control. Among the OSCC patients, 74.51% had moderate to severe vitamin D deficiencies, whereas only 20.35% had a moderate deficiency in the control group with no severe deficiency.

Conclusion

Logistic regression analysis shows a positive association between vitamin D deficiency and OSCC risk especially in levels below 25 ng/ml. This further corroborates the assertion that vitamin D deficiency may be a useful indicator of OSCC. It may, therefore, be necessary to routinely prescribe vitamin D supplements to subjects with moderate to severe deficiencies in order to decrease the chances of OSCC development.
Mesoscale Reaction–Diffusion Phenomena Governing Lignin‐First Biomass Fractionation
Authors: Thornburg Nicholas E. , Pecha M. Brennan , Brandner David G. , Reed Michelle L. , Vermaas Josh V. , Michener William E. , Katahira Rui , Vinzant Todd B. , Foust Thomas D. , Donohoe Bryon S. , Román‐Leshkov Yuriy , Ciesielski Peter N. , Beckham Gregg T.
Published: April 2020

Lignin solvolysis from the plant cell wall is the critical first step in lignin depolymerization processes involving whole biomass feedstocks. However, little is known about the coupled reaction kinetics and transport phenomena that govern the effective rates of lignin extraction. Here, we report a validated simulation framework that determines intrinsic, transport‐independent kinetic parameters for the solvolysis of lignin, hemicellulose, and cellulose upon incorporation of feedstock characteristics for the methanol‐based extraction of poplar as an example fractionation process. Lignin fragment diffusion is predicted to compete on the same time and length scales as reactions of lignin within cell walls and longitudinal pores of typical milled particle sizes, and mass transfer resistances are predicted to dominate the solvolysis of poplar particles that exceed approximately 2 mm in length. Beyond the approximately 2 mm threshold, effectiveness factors are predicted to be below 0.25, which implies that pore diffusion resistances may attenuate observable kinetic rate measurements by at least 75 % in such cases. Thus, researchers are recommended to conduct kinetic evaluations of lignin‐first catalysts using biomass particles smaller than approximately 0.2 mm in length to avoid feedstock‐specific mass transfer limitations in lignin conversion studies. Overall, this work highlights opportunities to improve lignin solvolysis by genetic engineering and provides actionable kinetic information to guide the design and scale‐up of emerging biorefinery strategies.
Current concepts on how to optimise Skin Needling 2020: A personal experience: Part 2
Authors: Fernandes Desmond
Published: April 2020

This is a brief history of the beginnings of skin needling (collagen induction therapy) and Part 1 covers the original clinical work which was then validated by research primarily by Matthias Aust and team at Hanover Medical School, Germany. Skin needling became the very first medical procedure that induces regeneration instead of scar formation because it employs transforming growth factor‐β3 (TGF‐β3) and interleukin‐10 (IL‐10). We essay into methods to optimise the effects of skin needling. First by the depth of penetration into the skin which will depend on the condition treated. Wrinkles stretch marks, and so on only require 1.0 mm whereas burns scars acne scars, and so on require deeper penetration, that is, approximately 3.0 mm. In Part 2, we need to consider the use of topicals both before and after skin needling. Vitamins A and C are scientifically proven to almost quadruple the effects of needling. Selected peptides seem to further enhance results. Hyaluronic acid is best induced naturally but may be used topically for comfort. Finally, we examine the rationale of the intervals between needling. The best clinical results seem to come from treatments at 4 to 10 days intervals to take advantage of raised titres of TGF‐β3 and IL‐10. Other modalities such as red and infrared LED, platelet‐rich plasma and mild peeling are gaining appeal to give better results. Skin needling is the safest and most effective method to treat photoaging, lax skin, stretch marks, acne scars, and burn scars.
The influence of chemical modifications on the fragmentation behavior of fentanyl and fentanyl‐related compounds in electrospray ionization tandem mass spectrometry
Authors: Davidson J. Tyler , Sasiene Zachary J. , Jackson Glen P.
Published: April 2020

Fentanyl is a synthetic opioid that has been approved by the FDA as a general anesthetic because of its rapid onset and high potency. However, since 2013 an opioid epidemic involving fentanyl or fentanyl‐related compounds (FRCs) has swept the United States and caused numerous deaths in every state. The identification of novel FRCs is complicated by the rapid turnover of modifications to the core fentanyl structure. In this study, a series of 16 FRCs were analyzed using electrospray ionization tandem mass spectrometry (ESI‐MS/MS) to gain a deeper understanding of the conserved and unique fragmentation behaviors associated with substitution to the core fentanyl structure. This work provides an approach, based on the product ions from ESI‐MS/MS, to identify the modification site(s) on the core fentanyl structure for FRCs. Five common locations of substitution to the core fentanyl structure were used to assess the effect of substitution on the fragmentation behavior of FRCs. The proposed fragmentation pathways are supported through the combination of isotopic labeling, multi‐stage mass spectrometry (MSn), and accurate mass measurements with high‐resolution mass spectrometry (HRMS). The identification of primary product ions specific to regions of substitution provides an additional tool for the identification of the location of substitution to the core fentanyl structure, which ultimately will assist toxicologists and seized drug analysts in the identification of emerging FRCs.
Extraction of α‐neurotoxins from equine plasma by receptor based affinity purification
Authors: Timms Mark , Ganio Katherine , Steel Rohan
Published: April 2020

Venoms were first identified as potential doping agents by the racing industry in 2007 when three vials of cobra venom were seized during an inspection of a stable at Keeneland Racecourse in the USA. Venoms are a complex mixture of proteins, peptides, and other substances with a wide range of biological effects, including inhibiting the transmission of nervous and muscular impulses. As an example of this, cobratoxin, an α‐neurotoxin found in cobra venom, is claimed to be an effective treatment for pain. Recent analysis of seized samples identified venom from two different species of snake. Proteomic analysis identified the first sample as cobra venom, while the second sample, in a vial labeled “Conotoxin”, was identified as venom from a many banded krait. Cobratoxin, conotoxins, and bungarotoxins (a component of krait venom) are all α‐neurotoxins, suggesting a common application for all three venom proteins as potential pain blocking medications. Using a peptide based on the nicotinic acetylcholine receptor, a one‐step affinity purification method was developed for the detection of α‐neurotoxins in plasma.
The diet of the striped hyena in Nepal's lowland regions
Authors: Bhandari Shivish , Morley Craig , Aryal Achyut , Shrestha Uttam Babu
Published: April 2020

Striped hyenas (Hyaena hyaena) are extremely rare in Nepal, and only a few people have studied them in their natural forest and grassland habitat. Their rarity is due to anthropogenic pressures such as hunting, habitat modification, being killed on roads, and depletion of their natural prey. Here, we studied the feeding ecology of hyenas in lowland, Nepal. We employed an opportunistic sampling to collect hyena scats in a range of habitats and the line transect sampling to identify the prey of the hyena in the study site. We collected 68 hyena scats between 2015 and 2018. Most of the hyena scat (39.7%) was found in the Churia Hill forest followed by riverbed (26.4%), mixed forest (14.7%), Sal (Shorea robusta)‐dominated forest (11.7%), and grassland area (7.3%). We found eleven mammalian prey species, plants, and some unidentified items in the hyena scats. The frequency of occurrence and relative biomass of the medium‐sized wild boar (Sus scrofa) were higher than other smaller prey species such as hare (Lepus nigricollis) and rhesus macaque (Macaca mulatta). Similarly, the proportion of large prey species such as nilgai (Boselaphus tragocamelus) in the hyena diet was lower compared with wild boar, hares, and rhesus macaques indicating medium‐sized wild boar is the most preferred prey species. Livestock contributed 17.3% of the total dietary biomass. Domesticated species such as goats, sheep, cows, and even dogs were found in the diet of hyenas. Predation of livestock by hyenas could cause conflict, especially if this ongoing issue continues in the future. Rather, more conservation effort is required in lowland areas of Nepal to protect the hyenas' natural prey species, particularly in wildlife habitats to reduce the lure of taking domestic livestock. Similarly, conservation education at the local level and active involvement of government authorities in the conservation of this species might be helpful to mitigate human–hyena conflict in the human‐dominated landscape.
Selective Removal of Photocatalytically Active Anatase TiO2 Phase from Mixed‐Phase TiO2‐ZnO Nanocomposites: Impact on Physicochemical Properties and Photocatalytic Activity
Authors: Menon Nambath Gayathri , Tatiparti Sankara Sarma V. , Mukherji Suparna
Published: April 2020

TiO2‐ZnO nanocomposites were synthesized by varying Ti:Zn molar ratio from 1:0.1 (TZ‐1:0.1) to 1:1 (TZ‐1:1). With increase in Zn content, from TZ‐1:0.1 to TZ‐1:0.2, anatase transformed to rutile phase. TZ‐1:0.3, which contained a blend of phases, including rutile and anatase TiO2, ZnO, and zinc titanates, exhibited the narrowest bandgap (2.5 ± 0.1 eV), and showed the highest photocatalytic activity. TZ‐1:1 was predominated by zinc titanates. All the nanocomposites exhibited narrower bandgaps compared to pure TiO2 nanoparticles, facilitating visible light activity. This study was designed to explore whether a method targeting the removal of a specific crystalline phase (anatase) influenced the properties and photocatalytic activity of the nanocomposite. Selective dissolution not only removed anatase phase, but also led to significant loss of crystallinity, widened the bandgap, and adversely affected photocatalytic performance, in nanocomposites that contained >80% anatase phase (TZ‐1:0.1 and TZ‐1:0.2). However, in nanocomposites that contained less of anatase phase (TZ‐1:0.3 and TZ‐1:1), the morphology, bandgap, crystallinity, and the extent of photocatalytic activity at the end of 240 min remained largely unaffected. Photocatalytic activity in TZ‐1:0.3 and TZ‐1:1 originated from a blend of phases comprising of less photocatalytically active phases, such as rutile TiO2, ZnTiO3, and Zn2TiO4, rather than from the anatase phase. The Ti:Zn molar ratio controlled the phases present in TiO2‐ZnO nanocomposites, which, in turn, controlled the physicochemical properties and visible light activity. Thus, in nanocomposites that contained a mix of several phases, the properties and photocatalytic activity were not dependent on anatase phase.
Recent Progress in Preparation and Application of Nano‐Chitin Materials
Authors: Yang Xuefei , Liu Jie , Pei Ying , Zheng Xuejing , Tang Keyong
Published: April 2020

Chitin is a kind of natural macromolecule material which was first discovered in mushrooms and was widely found in the shells of crustaceans and arthropods, the cell walls of fungi (yeast and mold) and algae, and the mollusks. The original chitin in nature usually has an antiparallel molecular chain alignment forming nanofibers connected by inter‐ and intramolecular hydrogen bonds. These microfibers consist of nanofibers about 2‐5 nm in diameter, and about 300 nm long, embedded by protein matrices. Due to their unique dimensional, optical, mechanical, and other characteristics, the preparation of nano‐chitin materials is an important subject. It is possible to extract nano‐chitins from their sources with various methods, including acid hydrolysis, mechanical disintegration, TEMPO‐mediated oxidation, electrospinning, and others. In this article, the latest progress in recent years in the preparation and applications of nano‐chitin were reviewed. The morphology of the nano‐chitins obtained from the above methods was presented. The advantages and disadvantages of each method were analyzed. An overview of applications of nano‐chitins was discussed, including biomedicine, food applications, water treatment, green electronic materials, enzyme immobilization carriers, cotton textile materials, cosmetics, and others.
Impact of left atrial diameter on outcome in patients undergoing edge‐to‐edge mitral valve repair: results from the German TRAnscatheter Mitral valve Interventions (TRAMI) registry
Authors: Iliadis Christos , Baldus Stephan , Kalbacher Daniel , Boekstegers Peter , Schillinger Wolfgang , Ouarrak Taoufik , Zahn Ralf , Butter Christian , Zuern Christine S. , von Bardeleben Ralph Stephan , Senges Jochen , Bekeredjian Raffi , Eggebrecht Holger , Pfister Roman
Published: April 2020

Background

Left atrial (LA) dimension is a marker of disease severity and outcome in primary and secondary mitral regurgitation. In transcatheter mitral valve repair, LA enlargement might additionally impact on device handling and technical success through an altered anatomy and atrial annular dilatation.

Methods and results

Data from the multicentre German TRAnscatheter Mitral valve Interventions registry (TRAMI) were used to analyse the association of baseline LA diameter by tertiles with efficacy, safety and long‐term clinical outcome in patients undergoing edge‐to‐edge repair with MitraClip. In 520 of 843 patients prospectively enrolled in TRAMI, baseline LA diameter were reported [median (interquartile range) LA diameter in tertiles: 44 (40–46) mm, 51 (48–53) mm and 60 (55–66) mm]. Larger LA diameters were significantly associated with secondary aetiology of mitral regurgitation, lower ejection fraction, larger left ventricle, male sex and atrial fibrillation (all P < 0.05). Technical success was not different across tertiles (96%, 95.4% and 98.4%, respectively; P = 0.43) as were major in‐hospital cardiovascular and cerebral adverse events (mortality, myocardial infarction or stroke: 1.8%, 1.2% and 4.4%, respectively; P = 0.11 across tertiles). However, 4‐year mortality significantly increased with larger LA diameter (32.9%, 46.4% and 51.7%, respectively; P < 0.01), as did hospitalization in survivors (60%, 67.6% and 78.9%, respectively; P < 0.05). The association between LA diameter and outcome remained significant after multivariable adjustment including baseline left ventricular end‐diastolic diameter.

Conclusion

Left atrial enlargement is a strong and independent predictor of adverse long‐term outcome after transcatheter mitral valve repair. Further study is warranted to examine whether timely intervention may have the potential to modify outcome.
WOx‐Modified Ni Catalyst Supported on Mesoporous Silica with Extra‐Large Mesopores for CO Methanation
Authors: Yang Hongyuan , Liu Xin , Liu Qing , Bian Bing , Pang Yuanyuan
Published: April 2020

A group of Ni–WOx/FDU‐12 (x < 3; FDU‐12: Fudan University ordered mesoporous materials) catalysts is prepared via a polyhydroxy compound–assisted impregnation method for carbon monoxide (CO) methanation. Ethylene glycol is used as the solvent, and citric acid is added as the second polyhydroxy compound to enhance the dispersion of Ni2+ ions. These polyhydroxy compounds are carbonized as sacrificial carbon via calcination in an inert atmosphere. Meanwhile, H2O is used as the reference solvent. These catalysts are systematically characterized by various techniques. The results show that the utilization of ethylene glycol and citric acid significantly reduces the size of Ni, and the addition of the WOx promoter further improves Ni dispersion. The optimal catalyst shows a high low‐temperature activity, which reaches thermodynamic equilibrium at only 360 °C and obtains the maximum CH4 yield of 86.2% at 400 °C due to the fine Ni particle size and enhanced hydrogen chemisorption capacity. In addition, this catalyst shows high stability in a 100 h‐lifetime test at 400 °C, 0.1 MPa, and a high weight hourly space velocity of 60 000 mL g−1 h−1. This is attributed to the synergistic effect of the WO3 promoter and the physical barrier of carbon residue, as well as the confinement effect of FDU‐12 support.
Three‐Dimensional Porous Fe–N–C Derived from Iron‐Citrate‐Functionalized Melamine Foam as a Highly Active Oxygen Reduction Catalyst for Zn–Air Batteries
Authors: Liu Jing , Zhu Yuanyuan , Fan Chaohua , Wang Jie , Du Fanglin , Jiang Luhua
Published: April 2020

A facile method to prepare Fe–N–C catalysts with a 3D porous structure is reported, where melamine foam is used as the self‐sacrificed template, and citric acid (CA) and iron salts are used as the precursors. The morphology and chemical valence state of the surface elements of the catalyst are characterized. Cyclic voltammetry (CV), liner scanning voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) are used to evaluate the catalytic performance on the oxygen reduction reaction (ORR). The catalyst CA‐Fe/MF‐N900 (calcinated at 900 °C) exhibits the best ORR performance. In alkaline electrolyte, the ORR current starts at 0.98 V versus reversible hydrogen electrode (RHE). The half‐wave potential (E1/2) is 0.83 V versus RHE, and the limiting current density reaches 5.3 mA cm−2. After 1000 cycles, E1/2 merely shifts negatively by 7 mV. The Zn–air battery fabricated with the CA‐Fe/MF‐N900 as the cathode catalyst displays outstanding discharging performance with peak power density of 158 mW cm−2 and long‐term stability. The enhanced catalytic activity can be attributed to the advanced 3D interconnected porous architecture of the Fe–N–C catalyst, which can not only accommodate abundant active sites but also significantly reduce the mass/charge transfer resistance.
Drivers of variability in large wood loads along the fluvial continuum of a Mediterranean intermittent river
Authors: Galia Tomáš , Macurová Tereza , Vardakas Leonidas , Škarpich Václav , Matušková Tereza , Kalogianni Eleni
Published: April 2020

Although in‐channel and floodplain large wood (LW) has been recognized as an important component of lotic ecosystems, there is still limited knowledge on the recruitment, mobility and retention of LW in rivers with an intermittent hydrological regime. In this study, we analysed the LW characteristics and related reach‐scale variables of 22 reaches in a Mediterranean intermittent river (Evrotas, Greece) in order to identify predictors of in‐channel and floodplain LW distribution. Our results indicated high downstream variation in LW volumes in the fluvial corridor (0.05–25.51 m3/ha for in‐channel LW and 0–30.88 m3/ha for floodplain LW). In‐channel and floodplain LW retention was primarily driven by the hydrological regime of the studied reaches (i.e. perennial or non‐perennial) with higher volumes of LW observed in perennial sections. The width of the riparian corridor was an important predictor of LW storage at the reach scale. Non‐perennial reaches had a disproportionally larger number of relatively small‐diameter living trees at the expense of mature trees with larger diameters typical for riparian stands functioning as LW recruitment areas in perennial reaches. The smaller dimensions of in‐channel LW in non‐perennial reaches, coupled with the dominance of loose LW pieces, implies frequent LW transport during ordinary flood events. Nevertheless, overall low LW retention in the fluvial corridor under non‐perennial flow regime predicts low volumes of mobilized LW. In contrast, the recruitment of relatively long and large‐diameter LW from mature riparian stands in perennial reaches, together with additional LW stabilization by banks, bed sediments, living trees or other LW pieces decreases the potential for further LW transport. © 2020 John Wiley & Sons, Ltd.
Optimum strip width increases dry matter, nutrient accumulation, and seed yield of intercrops under the relay intercropping system
Authors: Raza Muhammad Ali , Feng Ling Yang , van der Werf Wopke , Iqbal Nasir , Khan Imran , Khan Ahsin , Din Atta Mohi Ud , Naeem Muhammd , Meraj Tehseen Ahmad , Hassan Muhammad Jawad , Khan Aaqil , Lu Feng Zhi , Liu Xin , Ahmed Mukhtar , Yang Feng , Yang Wenyu
Published: April 2020

Strip width management is a critical factor for producing higher crop yields in relay intercropping systems. A 2‐year field experiment was carried out during 2012 and 2013 to evaluate the effects of different strip width treatments on dry‐matter production, major‐nutrient (nitrogen, phosphorus, and potassium) uptake, and competition parameters of soybean and maize in relay intercropping system. The strip width (SW) treatments were 0.40, 0.40, and 0.40 m (SW1); 0.40, 0.40, and 0.50 m (SW2); 0.40, 0.40, and 0.60 m (SW3); and 0.40, 0.40, and 0.70 m (SW4) for soybean row spacing, maize row spacing, and spacing between soybean and maize rows, respectively. As compared to sole maize (SM) and sole soybean (SS), relay‐intercropped maize and soybean accumulated lower quantities of nitrogen, phosphorus, and potassium in all treatments. However, maize in SW1 accumulated higher nitrogen, phosphorus, and potassium than SW4 (9%, 9%, and 8% for nitrogen, phosphorus, and potassium, respectively). Soybean in SW3 accumulated 25% higher nitrogen, 33% higher phosphorus, and 24% higher potassium than in SW1. The improved nutrient accumulation in SW3 significantly increased the soybean dry matter by 19%, but slightly decreased the maize dry matter by 6% compared to SW1. Similarly, SW3 increased the competition ratio value of soybean (by 151%), but it reduced the competition ratio value of maize (by 171%) compared to SW1. On average, in SW3, relay‐cropped soybean produced 84% of SS seed yield and maize produced 98% of SM seed yield and achieved the land equivalent ratio of 1.8, demonstrating the highest level in the world. Overall, these results suggested that by selecting the appropriate strip width (SW3; 0.40 m for soybean row spacing, 0.40 m maize row spacing, and 0.60 m spacing between soybean and maize rows), we can increase the nutrient uptake (especially nitrogen, phosphorus, and potassium), dry‐matter accumulation, and seed yields of relay‐intercrop species under relay intercropping systems.