bluuebunny/crossref_metadata_2025 huggingface dataset:
Unraveling ERBB network dynamics upon betacellulin signaling in pancreatic ductal adenocarcinoma in mice
Authors: Hedegger Kathrin , Algül Hana , Lesina Marina , Blutke Andreas , Schmid Roland M. , Schneider Marlon R. , Dahlhoff Maik
Published: April 2020

Pancreatic ductal adenocarcinoma (PDAC) will soon belong to the top three cancer killers. The only approved specific PDAC therapy targets the epidermal growth factor receptor (EGFR). Although EGFR is a crucial player in PDAC development, EGFR‐based therapy is disappointing. In this study, we evaluated the role of the EGFR ligand betacellulin (BTC) in PDAC. The expression of BTC was investigated in human pancreatic cancer specimen. Then, we generated a BTC knockout mouse model by CRISPR/Cas9 technology and a BTC overexpression model. Both models were crossed with the Ptf1aCre/+;KRASG12D/+ (KC) mouse model (B−/−KC or BKC, respectively). In addition, EGFR, ERBB2, and ERBB4 were investigated by the pancreas‐specific deletion of each receptor using the Cre‐loxP system. Tumor initiation and progression were analyzed in all mouse lines, and the underlying molecular biology of PDAC was investigated at different time points. BTC is expressed in human and murine PDAC. B−/−KC mice showed a decelerated PDAC progression, associated with decreased EGFR activation. BKC mice developed severe PDAC with a poor survival rate. The dramatically increased BTC‐mediated tumor burden was EGFR‐dependent, but also ERBB4 and ERBB2 were involved in PDAC development or progression, as depletion of EGFR, ERBB2, or ERBB4 significantly improved the survival rate of BTC‐mediated PDAC. BTC increases PDAC tumor burden dramatically by enhanced RAS activation. EGFR signaling, ERBB2 signaling, and ERBB4 signaling are involved in accelerated PDAC development mediated by BTC indicating that targeting the whole ERBB family, instead of a single receptor, is a promising strategy for the development of future PDAC therapies.
Linc‐ROR promotes the progression of breast cancer and decreases the sensitivity to rapamycin through miR‐194‐3p targeting MECP2
Authors: Zhou Qian , Guo Juan , Huang Wenjie , Yu Xiaosi , Xu Chen , Long Xinghua
Published: April 2020

linc‐ROR is reported to be a potential biomarker of breast cancer, but the detailed mechanism of linc‐ROR‐mediated breast cancer regulation has not been fully studied. We aimed to explore how linc‐ROR affects proliferation, metastasis, and drug sensitivity in breast cancer. Cell lines in which linc‐ROR was overexpressed or knocked down were constructed, and the cell proliferation, colony formation, cell migration, and invasion abilities of these lines were explored. A CCK‐8 assay was performed to determine the sensitivity of the breast cancer cells to rapamycin. Next‐generation sequencing was conducted to explore the detailed regulatory mechanism of linc‐ROR; differentially expressed RNAs in the linc‐ROR‐overexpressing cell line compared with the negative control were screened out, and their target genes were chosen to perform Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis, protein–protein interaction network analysis, and competing endogenous RNA (ceRNA) network analysis. The ceRNA mechanism of linc‐ROR for miR‐194‐3p, which targets MECP2, was determined through dual‐luciferase reporter assay, RT–qPCR, western blot, and rescue experiments. Finally, we found that linc‐ROR was upregulated in breast tumor tissues. linc‐ROR promoted the cell proliferation, colony formation, cell migration, and invasion of breast cancer and decreased the sensitivity of breast cancer cells to rapamycin. The overexpression of linc‐ROR triggered changes in the whole transcriptome of breast cancer cells, and a total of 85 lncRNAs, 414 microRNAs, 490 mRNAs, and 92 circRNAs were differentially expressed in the linc‐ROR‐overexpressing cell line compared with the negative control. Through a series of bioinformatic analyses, the ‘linc‐ROR/miR‐194‐3p/MECP2’ ceRNA regulatory axis was confirmed to be involved in the linc‐ROR‐mediated progression and drug sensitivity of breast cancer. In conclusion, linc‐ROR serves as an onco‐lncRNA in breast cancer and promotes the survival of breast cancer cells during rapamycin treatment by functioning as a ceRNA sponge for miR‐194‐3p, which targets MECP2.
Returns to Investing in Commodity Futures: Separating the Wheat from the Chaff
Authors: Irwin Scott H. , Sanders Dwight R. , Smith Aaron , Main Scott
Published: April 2020

Commodity futures investment grew rapidly after its popularity exploded in the mid‐2000s. However, real‐time performance has been disappointing. Our analysis shows that the disappointing commodity returns were not driven mechanically by contango or negative “roll yields.” We show that the expected return to individual commodity futures is near zero before expenses, which implies net losses (before interest earnings) will be equal to order execution and operating costs estimated at 3%–4% per year. Finally, it is likely that rapid increases in commodity prices during 2004–2008 skewed investor return expectations upward much like it did in the early 1970s.
The mediating role of visceral adiposity in the relationship among schooling, physical inactivity, and unhealthy metabolic phenotype
Authors: Ferreira Fabrícia Geralda , Juvanhol Leidjaira Lopes , Silva‐Costa Aline , Longo Giana Zarbato
Published: April 2020

Objective

To explore the mediating role of visceral adiposity, as assessed by the visceral adiposity index (VAI), in the relationship among schooling, physical inactivity, and unhealthy metabolic phenotype (UMP).

Methods

A cross‐sectional population‐based study was conducted with 854 adult individuals of both sexes from a Brazilian city. Data were collected through interviews, anthropometric evaluation, and clinical and laboratorial tests. We used multivariate path analysis, which simultaneously analyzes multiple relationships between variables. The analyses were adjusted by sex and age and stratified according to nutritional status.

Results

A positive direct effect of visceral adiposity on the UMP was observed for normal weight, standardized estimate (SE) = 0.632; confidence interval (CI 95%) = 0.547, 0.707) and overweight individuals (SE = 0.732; CI 95% = 0.647, 0.808), and negative direct effect of schooling on physical inactivity (normal weight: SE = −0.408; CI 95% = −0.550, −0.265) and overweight (SE = −0.304; CI 95% = −0.479, −0.129). Among normal‐weight individuals, there was a positive direct effect (SE = 0.193; CI 95% = 0.059, 0.328) of physical inactivity on VAI. In relation to indirect effects, there was a mediating role of visceral adiposity in the association of schooling level and physical inactivity with the UMP only among normal‐weight individuals.

Conclusions

Visceral adiposity has a direct effect on the UMP regardless of nutritional status, and there is a mediating effect of VAI on the relationship among schooling, physical inactivity, and UMP in normal‐weight individuals.
Strong Visible‐Light‐Absorbing Cuprous Sensitizers for Dramatically Boosting Photocatalysis
Authors: Chen Kai‐Kai , Guo Song , Liu Heyuan , Li Xiyou , Zhang Zhi‐Ming , Lu Tong‐Bu
Published: April 2020

Developing strong visible‐light‐absorbing (SVLA) earth‐abundant photosensitizers (PSs) for significantly improving the utilization of solar energy is highly desirable, yet it remains a great challenge. Herein, we adopt a through‐bond energy transfer (TBET) strategy by bridging boron dipyrromethene (Bodipy) and a CuI complex with an electronically conjugated bridge, resulting in the first SVLA CuI PSs (Cu‐2 and Cu‐3). Cu‐3 has an extremely high molar extinction coefficient of 162 260 m−1 cm−1 at 518 nm, over 62 times higher than that of traditional CuI PS (Cu‐1). The photooxidation activity of Cu‐3 is much greater than that of Cu‐1 and noble‐metal PSs (Ru(bpy)32+ and Ir(ppy)3+) for both energy‐ and electron‐transfer reactions. Femto‐ and nanosecond transient absorption and theoretical investigations demonstrate that a “ping‐pong” energy‐transfer process in Cu‐3 involving a forward singlet TBET from Bodipy to the CuI complex and a backward triplet‐triplet energy transfer greatly contribute to the long‐lived and Bodipy‐localized triplet excited state.
A journey into the world of insect lipid metabolism
Authors: Toprak Umut , Hegedus Dwayne , Doğan Cansu , Güney Gözde
Published: April 2020

Lipid metabolism is fundamental to life. In insects, it is critical, during reproduction, flight, starvation, and diapause. The coordination center for insect lipid metabolism is the fat body, which is analogous to the vertebrate adipose tissue and liver. Fat body contains various different cell types; however, adipocytes and oenocytes are the primary cells related to lipid metabolism. Lipid metabolism starts with the hydrolysis of dietary lipids, absorption of lipid monomers, followed by lipid transport from midgut to the fat body, lipogenesis or lipolysis in the fat body, and lipid transport from fat body to other sites demanding energy. Lipid metabolism is under the control of hormones, transcription factors, secondary messengers and posttranscriptional modifications. Primarily, lipogenesis is under the control of insulin‐like peptides that activate lipogenic transcription factors, such as sterol regulatory element‐binding proteins, whereas lipolysis is coordinated by the adipokinetic hormone that activates lipolytic transcription factors, such as forkhead box class O and cAMP‐response element‐binding protein. Calcium is the primary–secondary messenger affecting lipid metabolism and has different outcomes depending on the site of lipogenesis or lipolysis. Phosphorylation is central to lipid metabolism and multiple phosphorylases are involved in lipid accumulation or hydrolysis. Although most of the knowledge of insect lipid metabolism comes from the studies on the model Drosophila; other insects, in particular those with obligatory or facultative diapause, also have great potential to study lipid metabolism. The use of these models would significantly improve our knowledge of insect lipid metabolism.
Safety and Efficacy of Lenabasum in a Phase II, Randomized, Placebo‐Controlled Trial in Adults With Systemic Sclerosis
Authors: Spiera Robert , Hummers Laura , Chung Lorinda , Frech Tracy M. , Domsic Robyn , Hsu Vivien , Furst Daniel E. , Gordon Jessica , Mayes Maureen , Simms Robert , Lafyatis Robert , Martyanov Viktor , Wood Tammara , Whitfield Michael L. , Constantine Scott , Lee Elizabeth , Dgetluck Nancy , White Barbara
Published: April 2020

Objective

To assess the safety and efficacy of lenabasum in diffuse cutaneous systemic sclerosis (dcSSc).

Methods

A randomized, double‐blind, placebo‐controlled, phase II study was conducted at 9 SSc clinics in the US. Adults with dcSSc of ≤6 years’ duration who were receiving stable standard‐of‐care treatment were randomized to receive lenabasum (n = 27) or placebo (n = 15). Lenabasum doses were 5 mg once daily, 20 mg once daily, or 20 mg twice daily for 4 weeks, followed by 20 mg twice daily for 8 weeks. Safety and efficacy were assessed at weeks 4, 8, 12, and 16.

Results

Adverse events (AEs) occurred in 63% of the lenabasum group and 60% of the placebo group, with no serious AEs related to lenabasum. Compared to placebo, lenabasum treatment was associated with greater improvement in the American College of Rheumatology Combined Response Index in diffuse cutaneous Systemic Sclerosis (CRISS) score and other efficacy outcome measures that assessed overall disease, skin involvement, and patient‐reported function. The median CRISS score increased in the lenabasum group during the study, reaching 0.33, versus 0.00 in the placebo group, at week 16 (P = 0.07 by 2‐sided mixed‐effects model repeated‐measures analysis). Gene expression in inflammation and fibrosis pathways was reduced, and inflammation and fibrosis were improved on histologic evaluation of skin biopsy specimens, in the lenabasum group compared to the placebo group (all P ≤ 0.05).

Conclusion

Despite a short trial duration in a small number of patients in this phase II study in dcSSc, our findings indicate that lenabasum improves efficacy outcomes and underlying disease pathology with a favorable safety profile.
Role of Lipocalin‐Type Prostaglandin D Synthase in Experimental Osteoarthritis
Authors: Najar Mehdi , Ouhaddi Yassine , Paré Frédéric , Lussier Bertrand , Urade Yoshihiro , Kapoor Mohit , Pelletier Jean‐Pierre , Martel‐Pelletier Johanne , Benderdour Mohamed , Fahmi Hassan
Published: April 2020

Objective

Lipocalin‐type prostaglandin D synthase (L‐PGDS) catalyzes the formation of prostaglandin D2 (PGD2), which has important roles in inflammation and cartilage metabolism. We undertook this study to investigate the role of L‐PGDS in the pathogenesis of osteoarthritis (OA) using an experimental mouse model.

Methods

Experimental OA was induced in wild‐type (WT) and L‐PGDS–deficient (L‐PGDS−/−) mice (n = 10 per genotype) by destabilization of the medial meniscus (DMM). Cartilage degradation was evaluated by histology. The expression of matrix metalloproteinase 13 (MMP‐13) and ADAMTS‐5 was assessed by immunohistochemistry. Bone changes were determined by micro–computed tomography. Cartilage explants from L‐PGDS−/− and WT mice (n = 6 per genotype) were treated with interleukin‐1α (IL‐1α) ex vivo in order to evaluate proteoglycan degradation. Moreover, the effect of intraarticular injection of a recombinant adeno‐associated virus type 2/5 (rAAV2/5) encoding L‐PGDS on OA progression was evaluated in WT mice (n = 9 per group).

Results

Compared to WT mice, L‐PGDS−/− mice had exacerbated cartilage degradation and enhanced expression of MMP‐13 and ADAMTS‐5 (P < 0.05). Furthermore, L‐PGDS−/− mice displayed increased synovitis and subchondral bone changes (P < 0.05). Cartilage explants from L‐PGDS−/− mice showed enhanced proteoglycan degradation following treatment with IL‐1α (P < 0.05). Intraarticular injection of rAAV2/5 encoding L‐PGDS attenuated the severity of DMM‐induced OA‐like changes in WT mice (P < 0.05). The L‐PGDS level was increased in OA tissues of WT mice (P < 0.05).

Conclusion

Collectively, these findings suggest a protective role of L‐PGDS in OA, and therefore enhancing levels of L‐PGDS may constitute a promising therapeutic strategy.
Spectroscopic analysis of Muga silk nanoparticles synthesized by microwave method
Authors: Asapur Prithvi , Banerjee Indrani , Sahare P. D. , Mahapatra Santosh
Published: April 2020

Muga silk nanoparticles (MSNP) were synthesized using a microwave‐assisted radiolysis method. The effect of microwave on the Muga protein secondary structures was analyzed. The evolution of the secondary structure from random coils to the β‐sheets was determined by using FTIR, circular dichroism and X‐ray diffraction techniques. The results showed that Muga silk fibroin protein contained the primary structure in silk‐I state. When the protein was irradiated with microwave, nanoparticle synthesis was possible having silk‐II state imparting crystallinity. The silk nanoparticles were characterized by a particle size analyzer and found to be of ~240 nm in size. The optical properties of these nanoparticles were studied by UV–vis. spectroscopy and photoluminescence. For studying thermal properties, differential scanning calorimetry was performed that revealed early glass transition, which could be attributed to the presence of water and proteins. It also revealed that nanoparticles are thermally stable. Such studies are important for understanding more about the MSNP and would be beneficial for their further wide applications.
Right hepatic venous system variation in living donors: a three-dimensional CT analysis
Authors: Watanabe A , Yoshizumi T , Harimoto N , Kogure K , Ikegami T , Harada N , Itoh S , Takeishi K , Mano Y , Yoshiya S , Morinaga A , Araki K , Kubo N , Mori M , Shirabe K
Published: April 2020

Background

The right hepatic venous system consists of the right hepatic vein (RHV) and inferior RHVs (IRHVs). When the right posterior section is used as a graft for liver transplantation, understanding variations and relationships between the RHV and IRHVs is critical for graft venous return and hepatic vein reconstruction. This study aimed to evaluate variations in the hepatic veins and the relationships between them.

Methods

The medical records and CT images of patients who underwent hepatectomy as liver donors were assessed retrospectively. The relationship between the veins was evaluated by three-dimensional CT.

Results

The configuration of the posterior section was classified into one of eight types based on the RHV and IRHVs in 307 patients. Type 1a (103 of 307), type 1b (139 of 307) and type 2a (40 of 307) accounted for 91·9 per cent of the total. The diameter of the RHV extending towards the inferior vena cava had a significant inverse correlation with that of the IRHV (r2 = –0·615, P < 0·001). Type 1a, which had no IRHVs, had the RHV with the largest diameter; conversely, type 2a, which had a large IRHV, had the RHV with the smallest diameter.

Conclusion

The hepatic venous system of the right posterior section was classified into eight types, with an inverse relationship between RHV and IRHV sizes. This information is useful for segment VII resection or when the right liver is used as a transplant graft.
Long-term outcome of pT1a–b, cN0 breast cancer without axillary dissection or staging: a prospective observational study of 1543 women
Authors: Ingvar C , Ahlgren J , Emdin S , Lofgren L , Nordander M , Niméus E , Arnesson L-G
Published: April 2020

Background

The implementation of screening programmes in Sweden during the mid-1990s increased the number of small node-negative breast cancers. In this era before staging by sentinel node biopsy, routine axillary dissection for staging of early breast cancer was questioned owing to the increased morbidity and lack of perceived benefit. The long-term risk of axillary recurrence when axillary staging is omitted remains unclear.

Methods

This prospective observational multicentre cohort study included Swedish women diagnosed with breast cancer between 1997 and 2002. The patients had clinically node-negative, pT1a–b, grade I–II tumours. No axillary staging or dissection was performed. The primary outcome was ipsilateral axillary recurrence and survival.

Results

A total of 1543 patients were included. Breast-conserving surgery (BCS) was performed in 94·0 per cent and the rest underwent mastectomy. After surgery, 58·1 per cent of the women received adjuvant radiotherapy, 11·9 per cent adjuvant endocrine therapy and 31·5 per cent did not receive any adjuvant treatment. After a median follow-up of 15·5 years, 6·4 per cent developed contralateral breast cancer and 16·5 per cent experienced a recurrence. The first recurrence was local in 116, regional in 47 and distant in 59 patients. The breast cancer-specific survival rate was 93·7 per cent after 15 years. There were no differences in overall or breast cancer-specific survival between patients who received adjuvant radiotherapy and those who did not. Only 3·0 per cent of patients had an axillary recurrence, which was isolated in only 1·0 per cent.

Conclusion

Axillary surgery can safely be omitted in patients with low-grade, T1a–b, cN0 breast cancers. This large prospective cohort with 15-year follow-up had a very low incidence of axillary recurrences and high breast cancer-specific survival rate.
Trainee-led emergency laparotomy operating
Authors: Boyd-Carson H , Doleman B , Lockwood S , Williams J P , Tierney G M , Lund J N
Published: April 2020

Background

To achieve completion of training in general surgery, trainees are required to demonstrate competency in common procedures performed at emergency laparotomy. The aim of this study was to describe the patterns of trainee-led emergency laparotomy operating and the association between postoperative outcomes.

Methods

Data on all patients who had an emergency laparotomy between December 2013 and November 2017 were extracted from the National Emergency Laparotomy Audit database. Patients were grouped by grade of operating surgeon: trainee (specialty registrar) or consultant (including post-Certificate of Completion of Training fellows). Trends in trainee operating by deanery, hospital size and time of day of surgery were investigated. Univariable and adjusted regression analyses were performed for the outcomes 90-day mortality and return to theatre, with analysis of patients in operative subgroups segmental colectomy, Hartmann's procedure, adhesiolysis and repair of perforated peptic ulcer disease.

Results

The study cohort included 87 367 patients. The 90-day mortality rate was 15·1 per cent in the consultant group compared with 11·0 per cent in the trainee group. There were no increased odds of death by 90 days or of return to theatre across any of the operative groups when the operation was performed with a trainee listed as the most senior surgeon in theatre. Trainees were more likely to operate independently in high-volume centres (highest- versus lowest-volume centres: odds ratio (OR) 2·11, 95 per cent c.i. 1·91 to 2·33) and at night (00.00 to 07.59 versus 08.00 to 11.59 hours; OR 3·20, 2·95 to 3·48).

Conclusion

There is significant variation in trainee-led operating in emergency laparotomy by geographical area, hospital size and by time of day. However, this does not appear to influence mortality or return to theatre.
Is out-of-hours cholecystectomy for acute cholecystitis associated with complications?
Authors: Gustafsson C , Dahlberg M , Sondén A , Järnbert-Pettersson H , Sandblom G
Published: April 2020

Background

Existing data on the safety of out-of-hours cholecystectomy are conflicting. The aim of this study was to investigate whether out-of-hours cholecystectomy for acute cholecystitis is associated with a higher risk for complications compared with surgery during office hours.

Methods

This was a population-based cohort study. The Swedish Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography Register (GallRiks) was used to investigate the association between out-of-hours cholecystectomy for acute cholecystitis and complications developing within 30 days. Data from patients who underwent cholecystectomy between 2006 and 2017 were collected. Out-of-hours surgery was defined as surgery commencing between 19.00 and 07.00 hours on weekdays, or any time at weekends (Friday 19.00 hours to Monday 07.00 hours). Multivariable logistic regression analysis was used to assess the risk of complications, with time of procedure as independent variable. The proportion of open procedures and proportion of procedures exceeding 120 min were also analysed. Adjustments were made for sex, age, ASA grade, time between admission and surgery, and hospital-specific features.

Results

Of 11 153 procedures included, complications occurred within 30 days in 1573 patients (14·1 per cent). The adjusted odds ratio (OR) for complications for out-of-hours versus office-hours surgery was 1·12 (95 per cent c.i. 0·99 to 1·28). The adjusted OR for procedures completed as open surgery was 1·39 (1·25 to 1·54), and that for operating time exceeding 120 min was 0·63 (0·58 to 0·69).

Conclusion

Out-of-hours complications may relate to patient factors and the higher proportion of open procedures.
Comparative in vivo pharmacokinetics study of affeic acid, isoferulic acid and ferulic acid in crude and three different prepared Cimicifuga foetida L.
Authors: Wu Yu , Xu Yan , Yang Aihua , Shen Shuijie , Mi Daguo , Cao Yongjun , Hua Zhengying , Min Lingtian , Li Weidong
Published: April 2020

Our study investigated the differences in pharmacokinetics of three major components of crude Cimicifuga foetida L. and its fried product and honey‐ and liquor‐prepared products. A rapid and sensitive ultra‐high performance liquid chromatography with tandem mass spectrometry approach was established for determing caffeic acid, isoferulic acid and ferulic acid in rat plasma. The approach has good linearity, precision, accuracy, recovery and stability. Phenolic acid was rapidly absorbed. The times to peak concentration were shorter in the processed group than those for the crude product, with their values of <30 min. The peak concentration values of caffeic acid and isoferulic acid were higher in the crude group than in the processed groups (p < 0.05). Area under the curve values of the three phenolics in the crude group were significantly higher than those of the processed groups (p < 0.05).
Teaching computer programming to science majors by modelling
Authors: Lin Yu‐Tzu , Yeh Martin K.‐C. , Hsieh Hsin‐Ling
Published: April 2020

This study reports the design and implementation of a modelling‐based programming instruction for science majors and its effectiveness on programming and science learning. A modelling approach was proposed to provide guidance to students in implementing solutions for scientific problems in computer programming. This modelling approach includes five stages: (1) phenomenon description, (2) data modelling, (3) algorithmic modelling, (4) coding, and (5) verification and debugging. Authentic scenarios for science learning were adopted in teaching materials and problems to inspire students to learn both the scientific and programming aspects of the underneath phenomena. An empirical experiment to examine the effectiveness of the proposed instruction was conducted in a general education course at a university, and the results showed that students who engaged more in the modelling approach performed better in both the program implementation test and their final projects. In addition, students' feedback agreed with what we had expected the modelling approach would benefit students: they could connect abstract, real‐world phenomena to programming variables and logic by visualizing the phenomena in simulation and animation. Data modelling and algorithmic modelling also helped them analyze the variables in the problem space and propose a solution before coding. Because the proposed instruction provided opportunities to experience the capability of programming in solving scientific problems, high‐programming‐performance students also showed a greater interest in exploring science after the class.
Configuration‐Controlled Crystal and/or Gel Formation of Protected d‐Glucosamines Supported by Promiscuous Interaction Surfaces and a Conformationally Heterogeneous Solution State
Authors: Kapros Anita , Balázs Attila , Harmat Veronika , Háló Adrienn , Budai Lívia , Pintér István , Menyhárd Dóra K. , Perczel András
Published: April 2020

The configuration‐dependent self‐association mode of the two anomers of O‐Ac,N‐Fmoc‐d‐glucosamine, a foldamer building block, leading to gel and/or single crystal formation is described. The β‐anomer of the sugar amino acid (2) forms a gel from various solvents (confirmed by SEM, rheology measurements, NMR, and ECD spectroscopy), whereas the α‐anomer (1) does not form a gel with any solvent tested. Transition from the solution state to a gel is coupled to a concurrent shift of the Fmoc‐groups: from a freely rotating (almost symmetrical) to a specific, asymmetric orientation. Whereas the crystal structure of the α‐anomer is built as an evenly packed 3D system, the β‐anomer forms a looser superstructure of well‐packed 2D layers. Modeling indicates that in the lowest energy, but scarcely sampled conformer of the β‐anomer, the Fmoc‐group bends above the sugar moiety, stabilized by intramolecular CH↔π interactions between the aromatic rings. It is concluded that possessing an extended and promiscuous interaction surface and a conformationally heterogeneous solution state are among the basic requirements of gel formation for a candidate molecule.
Effects of Planting Field on Groundwater and Surface Water Pollution in China
Authors: Opoku‐Kwanowaa Yaa , Furaha Rachel Kasoro , Yan Li , Wei Daming
Published: April 2020

Water forms an essential resource for life on earth because all living things on earth depend on water for life activities. However, with the increase in the human population, which is coupled with intense urbanization and agricultural activities, global water pollution has increased over the past decades. In China, agricultural activities that occure mainly in the planting fields have been listed as the main source of surface water and groundwater pollution. This review focuses on the major factors that influence pollution from planting fields in China mainly as a result of farming activities such as flood irrigation, excessive application of fertilizers and pesticides, and poor management practices. At present, good results are achieved by adopting soil fertilization test formula, biodegradable pesticides, proper irrigation, and agroforestry interventions. In the future, pollution from planting fields as a non‐point source of water pollution can be improved and resolved by perfect nutrient management, best management practices, organic amendments, restoring water environment, and intelligent assessment management.
Discomfort luminance level of head‐mounted displays depending on the adapting luminance
Authors: Ha Hyeyoung , Kwak Youngshin , Kim Hyosun , Seo Young‐jun
Published: April 2020

The Images in an immersive head‐mounted display (HMD) for virtual reality provide the sole source for visual adaptation. Thus, significant, near‐instantaneous increases in luminance while viewing an HMD can result in visual discomfort. Therefore, the current study investigated the luminance change necessary to induce this discomfort. Based on the psychophysical experiment data collected from 10 subjects, a prediction model was derived using four complex images and one neutral image, with four to six levels of average scene luminance. Result showed that maximum area luminance has a significant correlation with the discomfort luminance level than average, median, or maximum pixel luminance. According to the prediction model, the discomfort luminance level of a head‐mounted display was represented as a positive linear function in log10 units using the previous adaptation luminance when luminance is calculated as maximum area luminance.
Synergistic effect of microbial and nonmicrobial biostimulants on growth, yield, and nutritional quality of organic tomato
Authors: Sani Md. Nasir Hossain , Islam Md. Nazrul , Uddain Jasim , Chowdhury Md. Shah Newaz , Subramaniam Sreeramanan
Published: April 2020

The current pot experiment was conducted at the Horticulture Farm of Sher‐e‐Bangla Agricultural University, Dhaka, Bangladesh, from October 2017 to April 2018, to evaluate the effects of the three biostimulants—Trichoderma‐based biostimulants (TB), seaweed extract (SWE), and humic substance (HS)—and their combinations on the growth, yield, nutritional quality, and antioxidant properties of tomato (Lycopersicum esculentumL.). The experiment was constructed in a completely randomized design using four replications. Thirteen treatments of TB, SWE, and HS were included (single and/or in combination) in the experiment, and the impact on growth, yield, nutritional quality, and antioxidant properties were evaluated. The results showed that T8(50 g L−1Trichoderma+ 2 g L−1SWE) increased the growth attributes positively as a result of the synergistic effects that led to a significant increase in yield over all other treatments. The treatment T8also elicited an increase in total soluble solids, as well as bioactive molecules such as lycopene and ascorbic acid, thereby increasing the nutritional and functional quality of the tomato fruits. Collectively,Trichodermaand SWE improved soil fertility and promoted the growth of rhizosphere microbes, which eventually led to higher tomato yields and increases in antioxidants and minerals. Soil drenching of SWE along withTrichodermais therefore considered to be an effective technique for sustainable tomato production of superior quality and higher yield.
Cross‐validation of stagewise mixed‐model analysis of Swedish variety trials with winter wheat and spring barley
Authors: Buntaran Harimurti , Piepho Hans‐Peter , Schmidt Paul , Rydén Jesper , Halling Magnus , Forkman Johannes
Published: April 2020

In cultivar testing, linear mixed models have been used routinely to analyze multienvironment trials. A single‐stage analysis is considered as the gold standard, whereas two‐stage analysis produces similar results when a fully efficient weighting method is used, namely when the full variance–covariance matrix of the estimated means from Stage 1 is forwarded to Stage 2. However, in practice, this may be hard to do and a diagonal approximation is often used. We conducted a cross‐validation with data from Swedish cultivar trials on winter wheat (Triticum aestivum L.) and spring barley (Hordeum vulgare L.) to assess the performance of single‐stage and two‐stage analyses. The fully efficient method and two diagonal approximation methods were used for weighting in the two‐stage analyses. In Sweden, cultivar recommendation is delineated by zones (regions), not individual locations. We demonstrate the use of best linear unbiased prediction (BLUP) for cultivar effects per zone, which exploits correlations between zones and thus allows information to be borrowed across zones. Complex variance–covariance structures were applied to allow for heterogeneity of cultivar × zone variance. The single‐stage analysis and the three weighted two‐stage analyses all performed similarly. Loss of information caused by a diagonal approximation of the variance–covariance matrix of adjusted means from Stage 1 was negligible. As expected, BLUP outperformed best linear unbiased estimation. Complex variance–covariance structures were dispensable. To our knowledge, this study is the first to use cross‐validation for comparing single‐stage analyses with stagewise analyses.
DPP4 inhibition: Preventing SARS‐CoV‐2 infection and/or progression of COVID‐19?
Authors: Strollo Rocky , Pozzilli Paolo
Published: April 2020

Dipeptidyl peptidase 4 (DPP4), also known as cluster of differentiation 26 (CD26), is a serine exopeptidase expressed ubiquitously in several tissues, including but not limited to lung, kidney, liver, gut, and immune cells. The question has been raised on whether DPP4 modulation or inhibition may prevent infection and/or progression of the COVID‐19. A docked complex model of the SARS‐CoV‐2 spike glycoprotein and DPP4 has been proposed, showing a large interface between the proteins and proposing close similarity with other coronaviruses using DPP4 as functional receptor. In absence of experimental validation, these data should be interpreted with caution. Nevertheless, this observation may rise the question on whether DPP4 is directly involved in SARS‐CoV‐2 cell adhesion/virulence, and whether DPP4 inhibition might be a therapeutic strategy for preventing infection. Although a direct involvement of DPP4 in SARS‐CoV‐2 infection needs to be clarified, there is also evidence suggesting that DPP4 inhibitors modulate inflammation and exert anti‐fibrotic activity. These properties may be of potential use for halting progression to the hyperinflammatory state associated with severe COVID‐19. Taken together these findings may suggest a potential role for DPP4 inhibition or modulation in one or more steps of COVID‐19 immunopathogenesis.
Effects of dispersal‐ and niche‐based factors on tree recruitment in tropical wet forest restoration
Authors: Werden Leland K. , Holl Karen D. , Rosales Juan Abel , Sylvester Janelle M. , Zahawi Rakan A.
Published: April 2020

Both dispersal‐ and niche‐based factors can impose major barriers on tree establishment. Our understanding of how these factors interact to determine recruitment rates is based primarily on findings from mature tropical forests, despite the fact that a majority of tropical forests are now secondary. Consequently, factors influencing seed limitation and the seed‐to‐seedling transition (STS) in disturbed landscapes, and how those factors shift during succession, are not well understood. We used a 3.5‐yr record of seed rain and seedling establishment to investigate factors influencing tree recruitment after a decade of recovery in a tropical wet forest restoration experiment in southern Costa Rica. We asked (1) how do a range of restoration treatments (natural regeneration, applied nucleation, plantation), canopy cover, and life‐history traits influence the STS and (2) how do seed and establishment limitation (lack of seed arrival or lack of seedling recruitment, respectively) influence vegetation recovery within restoration treatments as compared to remnant forest? We did not observe any differences in STS rates across restoration treatments. However, STS rates were lowest in adjacent later successional remnant forests, where seed source availability did not highly limit seed arrival, underscoring that niche‐based processes may increasingly limit recruitment as succession unfolds. Additionally, larger‐seeded species had consistently higher STS rates across treatments and remnant forests, though establishment limitation for these species was lowest in the remnant forests. Species were generally seed limited and almost all were establishment limited; these patterns were consistent across treatments. However, our results suggest that differences in recruitment rates could be driven by differential dispersal to treatments with higher canopy cover. We found evidence that barriers to recruitment shift during succession, with the influence of seed limitation, mediated by species‐level seed deposition rates, giving way to niche‐based processes. However, establishment limitation was lowest in the remnant forests for large‐seeded and late successional species, highlighting the importance of habitat specialization and life‐history traits in dictating recruitment dynamics. Overall, results demonstrate that active restoration approaches such as tree planting catalyze forest recovery, not only by decreasing components of seed limitation, but also by developing canopy cover that increases establishment rates of larger‐seeded species.
Validation prediction: a flexible protocol to increase efficiency of automated acoustic processing for wildlife research
Authors: Knight Elly C. , Sòlymos Péter , Scott Chris , Bayne Erin M.
Published: April 2020

Automated recognition is increasingly used to extract species detections from audio recordings; however, the time required to manually review each detection can be prohibitive. We developed a flexible protocol called “validation prediction” that uses machine learning to predict whether recognizer detections are true or false positives and can be applied to any recognizer type, ecological application, or analytical approach. Validation prediction uses a predictable relationship between recognizer score and the energy of an acoustic signal but can also incorporate any other ecological or spectral predictors (e.g., time of day, dominant frequency) that will help separate true from false‐positive recognizer detections. First, we documented the relationship between recognizer score and the energy of an acoustic signal for two different recognizer algorithm types (hidden Markov models and convolutional neural networks). Next, we demonstrated our protocol using a case study of two species, the Common Nighthawk (Chordeiles minor) and Ovenbird (Seiurus aurocapilla). We reduced the number of detections that required validation by 75.7% and 42.9%, respectively, while retaining at least 98% of the true‐positive detections. Validation prediction substantially improves the efficiency of using automated recognition on acoustic data sets. Our method can be of use to wildlife monitoring and research programs and will facilitate using automated recognition to mine bioacoustic data sets.
Landscape impacts of 3D‐seismic surveys in the Arctic National Wildlife Refuge, Alaska
Authors: Raynolds Martha K. , Jorgenson Janet C. , Jorgenson M. Torre , Kanevskiy Mikhail , Liljedahl Anna K. , Nolan Matthew , Sturm Matthew , Walker Donald A.
Published: April 2020

Although three‐dimensional (3D) seismic surveys have improved the success rate of exploratory drilling for oil and gas, the impacts have received little scientific scrutiny, despite affecting more area than any other oil and gas activity. To aid policy‐makers and scientists, we reviewed studies of the landscape impacts of 3D‐seismic surveys in the Arctic. We analyzed a proposed 3D‐seismic program in northeast Alaska, in the northern Arctic National Wildlife Refuge, which includes a grid 63,000 km of seismic trails and additional camp‐move trails. Current regulations are not adequate to eliminate impacts from these activities. We address issues related to the high‐density of 3D trails compared to 2D methods, with larger crews, more camps, and more vehicles. We focus on consequences to the hilly landscapes, including microtopography, snow, vegetation, hydrology, active layers, and permafrost. Based on studies of 2D‐seismic trails created in 1984–1985 in the same area by similar types of vehicles, under similar regulations, approximately 122 km2 would likely sustain direct medium‐ to high‐level disturbance from the proposed exploration, with possibly expanded impacts through permafrost degradation and hydrological connectivity. Strong winds are common, and snow cover necessary to minimize impacts from vehicles is windblown and inadequate to protect much of the area. Studies of 2D‐seismic impacts have shown that moist vegetation types, which dominate the area, sustain longer‐lasting damage than wet or dry types, and that the heavy vehicles used for mobile camps caused the most damage. The permafrost is ice rich, which combined with the hilly topography, makes it especially susceptible to thermokarst and erosion triggered by winter vehicle traffic. The effects of climate warming will exacerbate the impacts of winter travel due to warmer permafrost and a shift of precipitation from snow to rain. The cumulative impacts of 3D‐seismic traffic in tundra areas need to be better assessed, together with the effects of climate change and the industrial development that would likely follow. Current data needs include studies of the impacts of 3D‐seismic exploration, better climate records for the Arctic National Wildlife Refuge, especially for wind and snow; and high‐resolution maps of topography, ground ice, hydrology, and vegetation.
Intrathecal dexmedetomidine and postoperative pain: A systematic review and meta‐analysis of randomized controlled trials
Authors: Paramasivan Ambika , Lopez‐Olivo Maria A. , Foong Theng W. , Tan Yi W. , Yap Andrea P. A.
Published: April 2020

Background and Objective

A systematic review and meta‐analysis of randomized controlled trials (RCTs) was undertaken to evaluate the effect of intrathecal dexmedetomidine (DEX) on the duration of postoperative analgesia, postoperative pain scores and incidences of adverse effects.

Databases and Data Treatment

Database search was performed from inception until January 2019. All RCTs analysing acute postoperative pain characteristics after intrathecal DEX administration in adults undergoing spinal anaesthesia for elective surgery were included. The primary outcome was postoperative analgesic duration, defined as the time to first analgesic request. The secondary outcomes included pain scores at 6, 12 and 24 postoperative hours and rates of hypotension, bradycardia, shivering and postoperative nausea and vomiting.

Results

Twenty‐four studies comprising a total of 1,460 patients were included. Postoperative analgesic duration was prolonged with intrathecal DEX compared to placebo, with a pooled mean difference (MD) of 191.3 min (95% CI 168.8–213.8). Patients who received intrathecal DEX reported lower Visual Analogue Scale scores at 24 postoperative hours compared with those patients receiving placebo, with a MD (95% CI) of −1.05 (−1.89 to −0.20, p = 0.02). There were no differences in the incidence of adverse effects, except for a lower rate of postoperative shivering in the intrathecal DEX group (pooled relative risk 0.58, 95% CI 0.34–0.98, p = 0.04).

Conclusions

Compared to placebo, intrathecal DEX prolonged postoperative analgesic duration, reduced 24‐hr pain intensity and reduced the incidence of shivering without an increase in other adverse effects.

Significance

The analgesic role of intrathecal DEX is promising due to its ability to significantly increase postoperative analgesic duration when compared with placebo. Its usage can be considered for patients undergoing surgeries with significant postoperative pain, particularly those intolerant of systemic analgesia. However, the optimal dose for various surgeries as well as its long‐term neurological effects warrants further studies.
Peripheral input and phantom limb pain: A somatosensory event‐related potential study
Authors: Liu Hongcai , Andoh Jamila , Lyu Yuanyuan , Milde Christopher , Desch Simon , Zidda Francesca , Schmelz Martin , Curio Gabriel , Flor Herta
Published: April 2020

Background

Following amputation, nearly all amputees report nonpainful phantom phenomena and many of them suffer from chronic phantom limb pain (PLP) and residual limb pain (RLP). The aetiology of PLP remains elusive and there is an ongoing debate on the role of peripheral and central mechanisms. Few studies have examined the entire somatosensory pathway from the truncated nerves to the cortex in amputees with PLP compared to those without PLP. The relationship among afferent input, somatosensory responses and the change in PLP remains unclear.

Methods

Transcutaneous electrical nerve stimulation was applied on the truncated median nerve, the skin of the residual limb and the contralateral homologous nerve in 22 traumatic upper‐limb amputees (12 with and 10 without PLP). Using somatosensory event‐related potentials, the ascending volley was monitored from the brachial plexus, the spinal cord, the brainstem and the thalamus to the primary somatosensory cortex.

Results

Peripheral input could evoke PLP in amputees with chronic PLP (7/12), but not in amputees without a history of PLP (0/10). The amplitudes of the somatosensory components were comparable between amputees with and without PLP. In addition, evoked potentials from the periphery through the spinal, subcortical and cortical segments were not significantly associated with PLP.

Conclusions

Peripheral input can modulate PLP but seems insufficient to cause PLP. These findings suggest the multifactorial complexity of PLP and different mechanisms for PLP and RLP.

Significance

Peripheral afferent input plays a role in PLP and has been assumed to be sufficient to generate PLP. In this study we found no significant differences in the electrical potentials generated by peripheral stimulation from the truncated nerve and the skin of the residual limb in amputees with and without PLP. Peripheral input could enhance existing PLP but could not cause it. These findings indicate the multifactorial complexity of PLP and an important role of central processes in PLP.
Zero‐sum beliefs shape advantaged allies’ support for collective action
Authors: Stefaniak Anna , Mallett Robyn K. , Wohl Michael J. A.
Published: April 2020

Three studies (N1 = 1,019;N2 = 312;N3 = 494) tested whether seeing intergroup relations as inherently antagonistic shaped advantaged social groups’ allyship intentions. More specifically, we tested whether endorsingzero‐sum beliefsrelated to their willingness to support system‐challenging and system‐supporting collective action. Zero‐sum beliefs were negatively correlated with system‐challenging and positively correlated with system‐supporting collective action intentions. Zero‐sum beliefs were more common among advantaged than disadvantaged groups and translated into lower allyship intentions. Advantaged group members with higher levels of zero‐sum beliefs were also more likely to experience anger and fear when considering the demographic racial shift in the United States. Increased fear was associated with greater support for system‐supporting and lower support for system‐challenging collective action. We find consistent evidence that advantaged group members see intergroup relations as a zero‐sum game and that these beliefs are negatively related to their intentions to become allies.