bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytochemical Constituent and Cumulative or Antagonistic Effects of Crops Plant Organ Combination on Free Radical Scavenging Capacity and Antioxidant Compound Content
Authors: Bationo Rémy K. , Kaboré Dominique S. , Abdoulaye Yougoubo , Arrounan Noba , Toe Mahomed , Dabiré Constantin M. , Pale Eloi , Nébié Roger H. Ch.
Published: October 2024

Aims: In Burkina Faso, the majority of plant-based recipes are a combination of plant organs from the same or different species. For these recipes’ producers, the aim is to improve efficiency. However, our ethnobotanical surveys have revealed that for some species, efficacy is better when the species is not combined, or when it is combined in small proportions with other species. The aim of this study is to assess the effect of plant organ combination on free radical scavenging activity, phenolic compound content and flavonoid content.
Study Design: The work combined harvesting and processing of plant material from September to November 2023, and laboratories analysis from January to March 2024 at Natural Substances Departement of Institut de Recherche en Sciences Appliquées et Technologie, Ouagadougou.
Methodology: We prepared two batches of recipes, first combining two species from the same genus, then two species from different genera. The powder of each plant without combination was also used to compare data. Phytochemical screening was first carried out with TLC and LC-MS analysis on each plant extract. We then assessed the phenolic compound content (PCC) using Folin-Ciocalteu method, flavonoid content (FCC) using aluminum chloride test, antioxidant content using TEAC method and free radical scavenging activity using DPPH method, for different batches.
Results: Phytochemical constituent in the three species are phenolic compounds, terpenoids and nitrogen derivatives. The results of biological property evaluation suggest that for best efficacy and to obtain a high phenolic compound content, Lippia multiflora leaves should be used separately, or combined in 70% proportions with Lippia alba, then in 50% proportions if the combination is made with Ocimum basilicum.
Conclusion: This research has provided relevant results to guide players in the field of traditional medicine and users of herbal remedies.
Opportunistic Infections among People Living with HIV in the Infectious Disease Department, the University Hospital of Fann in Dakar, Senegal
Authors: Cisse Viviane Marie Pierre , Fall Ndèye Maguette , Sarr Alassane , Mbaye Khardiata Diallo , Bèye Hadiara , Barro Khadija , Lakhe Ndèye Aïssatou , Massaly Aminata , Badiane Aboubakar Sidikh , Diouf Assane , Ka Daye , Fortes Louise , Diop Sylvie Audrey , Ndour Cheikh Tidiane , Soumaré Masserigne , Seydi Moussa
Published: October 2024

Aim: The aim of this study was to identify the main infections and opportunistic infections in hospitalized patients living with HIV and to determine the hospital lethality rate.
Patients and Methods: This was a retrospective, descriptive study of patients hospitalized in the infectious diseases department of the University Hospital of Fann over a 02-year period from 1 January 2021 to 31 December 2022.
Results: We recorded 308 cases, 296 of which were patients living with HIV, out of a total of 1208 patients admitted to the department, a hospital prevalence rate of 24.5%. The average age of the patients was 43.3 ± 13.3 years, with a sex ratio of 0.7. One hundred and thirty-one patients (44.26%) were married. 22.97% had no occupation and 35.5% of patients came from home. The average diagnostic period was 3.9 days ± 4.78 days. Two hundred and five patients (69.26%) were at WHO stage 4. Tuberculosis was the most common bacterial infection, with 114 cases (38.5%), followed by common bacterial pneumonia (7.77%) and septicemia (4.72%). With regard to viral infections, the prevalence of viral hepatitis B was 6.76%, followed by herpes (1.68%). Among parasitic infections, toxoplasmosis was noted in 6.41% and cryptosporidiosis in 2.02%. Candidiasis was the most common fungal opportunistic infection, affecting forty-three patients (14.52%), followed by pneumocystis (7.09%) and cryptococcosis (2.36%). More than a third of our patients (37.84%) had severe anaemia, with haemoglobin levels below 8g/dl. Nearly a quarter of patients (21.28%) had impaired kidney function.
Conclusion: HIV infection occurs in young adults at a late stage. Mortality remains high due to opportunistic infection.
It is essential to carry out early screening, but above all to make available diagnostic tools and certain molecules for treatment of opportunistic infections.
Assessment of the Knowledge Level of COVID-19 Vaccines and Vaccine Hesitancy amongst Final-Year Medical Students in Southeast Nigeria
Authors: Imediegwu Kelechi U. , Anyamene Ebuka L. , Ndupu Ronald I. , Tietie Ufuoma E. , Ohadinma Daniel U. , Ugonna Nwoke O. , Ugwu Vivian N. , Anikpo Eberechukwu F. , Okechukwu Enyinnaya C. , Ike-Agbo Ikenna K. , Onwuasoigwe Chiamaka A. , Anya Benson C. , Uchegbu Ezinne V. , Ibe Linda C. , Ogundipe Abiodun M.
Published: October 2024

Background: Despite how ravaging and deadly COVID-19 infection is, vaccine hesitancy is high among the uneducated, medical students, and health workers, who as frontline workers, should lead by example and drive COVID-19 vaccination efforts.
Objectives: This research aims to assess the knowledge level of COVID-19 vaccines among final-year medical students in Southeast-Nigeria universities and determine the factors responsible for the hesitancy of this vaccine among them.
Methodology: A cross-sectional study of final-year medical students in six medical schools in Southeast Nigeria using an electronically distributed structured, validated online Google form amongst final-year medical students from which 125 of them responded.
Results: Out of a sample of 125 final-year medical students, 123 (98.4%) are aware of COVID-19 vaccines while 2 (1.6%) lack knowledge of COVID-19 vaccines. The demographics of the final year medical students comprised 68 (58%) males and 57 (45.6%) females, 74.4% (93/125) of the respondents do not have a preference for any vaccine while 25.6% (33/125), shows a preference for various vaccine types. 95 (76%) final year medical students have not been vaccinated as against 30 (24%) who have received the vaccine for the Covid-19 virus, this large gap in the vaccination ratio accounted for many factors ranging from safety, availability, side effects, etc.
Conclusion: The level of awareness of COVID-19 vaccines is very high among final-year medical students but it is not equivalent to the level of uptake of the vaccines. Despite being future healthcare professionals, medical students' vaccination rates remain suboptimal, highlighting a significant vaccine hesitancy and a large gap between knowledge and practice. Understanding and addressing these underlying factors is crucial to improving vaccine uptake and ensuring that medical students, as future healthcare leaders, are equipped to promote evidence-based public health practice.
Disease Indexing of Rapeseed: Mustard Cultivars against Alternaria Blight
Authors: Babli  , Pandya R.K
Published: October 2024

In the investigation, 120 rapeseed-mustard genotypes were screened under in vivo conditions for resistance against the foliar disease Alternaria blight. None of the genotypes were found to be immune to the disease. However, three genotypes—JT-1, RVM-3, and Pusa Jagannath—were identified as resistant (R), with disease severity ranging from 1% to 10%. Nine genotypes were classified as moderately resistant (MR), showing disease severity between 11% and 25%. A total of 67 genotypes were rated as moderately susceptible (MS), with disease severity ranging from 26% to 50%. Additionally, 41 genotypes were categorized as susceptible (S), where disease severity was between 51% and 75%.  The highly susceptible none of genotypes were found.
Longitudinal Variation of the Lunar Tide in the Equatorial Electrojet
Authors: Yamazaki Yosuke , Stolle Claudia , Matzka Jürgen , Siddiqui Tarique A. , Lühr Hermann , Alken Patrick
Published: November 2017

The atmospheric lunar tide is one known source of ionospheric variability. The subject received renewed attention as recent studies found a link between stratospheric sudden warmings and amplified lunar tidal perturbations in the equatorial ionosphere. There is increasing evidence from ground observations that the lunar tidal influence on the ionosphere depends on longitude. We use magnetic field measurements from the CHAMP satellite during July 2000 to September 2010 and from the two Swarm satellites during November 2013 to February 2017 to determine, for the first time, the complete seasonal‐longitudinal climatology of the semidiurnal lunar tidal variation in the equatorial electrojet intensity. Significant longitudinal variability is found in the amplitude of the lunar tidal variation, while the longitudinal variability in the phase is small. The amplitude peaks in the Peruvian sector (∼285°E) during the Northern Hemisphere winter and equinoxes, and in the Brazilian sector (∼325°E) during the Northern Hemisphere summer. There are also local amplitude maxima at ∼55°E and ∼120°E. The longitudinal variation is partly due to the modulation of ionospheric conductivities by the inhomogeneous geomagnetic field. Another possible cause of the longitudinal variability is neutral wind forcing by nonmigrating lunar tides. A tidal spectrum analysis of the semidiurnal lunar tidal variation in the equatorial electrojet reveals the dominance of the westward propagating mode with zonal wave number 2 (SW2), with secondary contributions by westward propagating modes with zonal wave numbers 3 (SW3) and 4 (SW4). Eastward propagating waves are largely absent from the tidal spectrum. Further study will be required for the relative importance of ionospheric conductivities and nonmigrating lunar tides.
Complementary Use of Glider Data, Altimetry, and Model for Exploring Mesoscale Eddies in the Tropical Pacific Solomon Sea
Authors: Gourdeau L. , Verron J. , Chaigneau A. , Cravatte S. , Kessler W.
Published: November 2017

Mesoscale activity is an important component of the Solomon Sea circulation that interacts with the energetic low‐latitude western boundary currents of the South Tropical Pacific Ocean carrying waters of subtropical origin before joining the equatorial Pacific. Mixing associated with mesoscale activity could explain water mass transformation observed in the Solomon Sea that likely impacts El Niño Southern Oscillation dynamics. This study makes synergetic use of glider data, altimetry, and high‐resolution model for exploring mesoscale eddies, especially their vertical structures, and their role on the Solomon Sea circulation. The description of individual eddies observed by altimetry and gliders provides the first elements to characterize the 3‐D structure of these tropical eddies, and confirms the usefulness of the model to access a more universal view of such eddies. Mesoscale eddies appear to have a vertical extension limited to the Surface Waters (SW) and the Upper Thermocline Water (UTW), i.e., the first 140–150 m depth. Most of the eddies are nonlinear, meaning that eddies can trap and transport water properties. But they weakly interact with the deep New Guinea Coastal Undercurrent that is a key piece of the equatorial circulation. Anticyclonic eddies are particularly efficient to advect salty and warm SW coming from the intrusion of equatorial Pacific waters at Solomon Strait, and to impact the characteristics of the New Guinea Coastal Current. Cyclonic eddies are particularly efficient to transport South Pacific Tropical Water (SPTW) anomalies from the North Vanuatu Jet and to erode by diapycnal mixing the high SPTW salinity.
Multidecadal fCO2 Increase Along the United States Southeast Coastal Margin
Authors: Reimer Janet J. , Wang Hongjie , Vargas Rodrigo , Cai Wei‐Jun
Published: November 2017

Coastal margins could be hotspots for acidification due to terrestrial‐influenced CO2 sources. Currently there are no long‐term (>20 years) records from biologically important coastal environments that could demonstrate sea surface CO2 fugacity (fCO2) and pH trends. Here, multidecadal fCO2 trends are calculated from underway and moored time series observations along the United States southeast coastal margin, also referred to as the South Atlantic Bight (SAB). fCO2 trends across the SAB, derived from ∼26 years of cruises and ∼9.5 years from a moored time series, range from 3.0 to 4.5 µatm yr−1, and are greater than the open ocean increases. The pH decline related to the fCO2 increases could be as much as −0.004 yr−1; a rate greater than that expected from atmospheric‐influenced pH alone. We provide evidence that fCO2 increases and pH decreases on an ocean margin can be faster than those predicted for the open ocean from atmospheric influence alone. We conclude that a substantial fCO2 increase across the marginal SAB is due to both increasing temperature on the middle and outer shelves, but to lateral land‐ocean interactions in the coastal zone and on inner shelf.
Estimation of Transmittance of Solar Radiation in the Visible Domain Based on Remote Sensing: Evaluation of Models Using In Situ Data
Authors: Zoffoli M. Laura , Lee Zhongping , Ondrusek Michael , Lin Junfang , Kovach Charles , Wei Jianwei , Lewis Marlon
Published: November 2017

The transmittance of solar radiation in the oceanic water column plays an important role in heat transfer and photosynthesis, with implications for the global carbon cycle, global circulation, and climate. Globally, the transmittance of solar radiation in the visible domain (∼400–700 nm) (TRVIS) through the water column, which determines the vertical distribution of visible light, has to be based on remote sensing products. There are models centered on chlorophyll‐a (Chl) concentration or Inherent Optical Properties (IOPs) as both can be derived from ocean color measurements. We present evaluations of both schemes with field data from clear oceanic and from coastal waters. Here five models were evaluated: (1) Morel and Antoine (1994) (MA94), (2) Ohlmann and Siegel (2000) (OS00), (3) Murtugudde et al. (2002) (MU02), (4) Manizza et al. (2005) (MA05), and (5) Lee et al. () (IOPs05), where the first four are Chl‐based and the last one is IOPs‐based, with all inputs derived from remote sensing reflectance. It is found that the best performing model is the IOPs05, with Unbiased Absolute Percent Difference (UAPD) ∼23%, while Chl‐based models show higher uncertainties (UAPD for MA94: ∼54%, OS00: ∼133%, MU02: ∼56%, and MA05: ∼39%). The IOPs‐based model was insensitive to the type of water, allowing it to be applied in most marine environments; whereas some of the Chl‐based models (MU02 and MA05) show much higher sensitivities in coastal turbid waters (higher Chl waters). These results highlight the applicablity of using IOPs products for such applications.
Early Spring Phytoplankton Dynamics in the Western Antarctic Peninsula
Authors: Arrigo Kevin R. , van Dijken Gert L. , Alderkamp Anne‐Carlijn , Erickson Zachary K. , Lewis Kate M. , Lowry Kate E. , Joy‐Warren Hannah L. , Middag Rob , Nash‐Arrigo Janice E. , Selz Virginia , van de Poll Willem
Published: November 2017

The Palmer Long‐Term Ecological Research program has sampled waters of the western Antarctic Peninsula (wAP) annually each summer since 1990. However, information about the wAP prior to the peak of the phytoplankton bloom in January is sparse. Here we present results from a spring process cruise that sampled the wAP in the early stages of phytoplankton bloom development in 2014. Sea ice concentrations were high on the shelf relative to nonshelf waters, especially toward the south. Macronutrients were high and nonlimiting to phytoplankton growth in both shelf and nonshelf waters, while dissolved iron concentrations were high only on the shelf. Phytoplankton were in good physiological condition throughout the wAP, although biomass on the shelf was uniformly low, presumably because of heavy sea ice cover. In contrast, an early stage phytoplankton bloom was observed beneath variable sea ice cover just seaward of the shelf break. Chlorophyll a concentrations in the bloom reached 2 mg m−3 within a 100–150 km band between the SBACC and SACCF. The location of the bloom appeared to be controlled by a balance between enhanced vertical mixing at the position of the two fronts and increased stratification due to melting sea ice between them. Unlike summer, when diatoms overwhelmingly dominate the phytoplankton population of the wAP, the haptophyte Phaeocystis antarctica dominated in spring, although diatoms were common. These results suggest that factors controlling phytoplankton abundance and composition change seasonally and may differentially affect phytoplankton populations as environmental conditions within the wAP region continue to change.
Spume Drops: Their Potential Role in Air‐Sea Gas Exchange
Authors: Monahan Edward C. , Staniec Allison , Vlahos Penny
Published: November 2017

After summarizing the time scales defining the change of the physical properties of spume and other droplets cast up from the sea surface, the time scales governing drop‐atmosphere gas exchange are compared. Following a broad review of the spume drop production functions described in the literature, a subset of these functions is selected via objective criteria, to represent typical, upper bound, and lower bound production functions. Three complementary mechanisms driving spume‐atmosphere gas exchange are described, and one is then used to estimate the relative importance, over a broad range of wind speeds, of this spume drop mechanism compared to the conventional, diffusional, sea surface mechanism in air‐sea gas exchange. While remaining uncertainties in the wind dependence of the spume drop production flux, and in the immediate sea surface gas flux, preclude a definitive conclusion, the findings of this study strongly suggest that, at high wind speeds (>20 m s−1 for dimethyl sulfide and >30 m s−1 for gases such a carbon dioxide), spume drops do make a significant contribution to air‐sea gas exchange.
Spatial Variation of Diapycnal Diffusivity Estimated From Seismic Imaging of Internal Wave Field, Gulf of Mexico
Authors: Dickinson Alex , White N. J. , Caulfield C. P.
Published: November 2017

Bright reflections are observed within the upper 1,000 m of the water column along a seismic reflection profile that traverses the northern margin of the Gulf of Mexico. Independent hydrographic calibration demonstrates that these reflections are primarily caused by temperature changes associated with different water masses that are entrained into the Gulf along the Loop Current. The internal wave field is analyzed by automatically tracking 1,171 reflections, each of which is greater than 2 km in length. Power spectra of the horizontal gradient of isopycnal displacement,
, are calculated from these tracked reflections. At low horizontal wave numbers (
cpm),
, in agreement with hydrographic observations of the internal wave field. The turbulent spectral subrange is rarely observed. Diapycnal diffusivity, K, is estimated from the observed internal wave spectral subrange of each tracked reflection using a fine‐scale parametrization of turbulent mixing. Calculated values of K vary between
and
m2 s−1 with a mean value of
m2 s−1. The spatial distribution of turbulent mixing shows that
m2 s−1 away from the shelf edge in the upper 300 m where stratification is strong. Mixing is enhanced by up to 4 orders of magnitude adjacent to the shoaling bathymetry of the continental slope. This overall pattern matches that determined by analyzing nearby suites of CTD casts. However, the range of values recovered by spectral analysis of the seismic image is greater as a consequence of significantly better horizontal resolution.
Shallow Aquifer Vulnerability From Subsurface Fluid Injection at a Proposed Shale Gas Hydraulic Fracturing Site
Authors: Wilson M. P. , Worrall F. , Davies R. J. , Hart A.
Published: November 2017

Groundwater flow resulting from a proposed hydraulic fracturing (fracking) operation was numerically modeled using 91 scenarios. Scenarios were chosen to be a combination of hydrogeological factors that a priori would control the long‐term migration of fracking fluids to the shallow subsurface. These factors were induced fracture extent, cross‐basin groundwater flow, deep low hydraulic conductivity strata, deep high hydraulic conductivity strata, fault hydraulic conductivity, and overpressure. The study considered the Bowland Basin, northwest England, with fracking of the Bowland Shale at ∼2,000 m depth and the shallow aquifer being the Sherwood Sandstone at ∼300–500 m depth. Of the 91 scenarios, 73 scenarios resulted in tracked particles not reaching the shallow aquifer within 10,000 years and 18 resulted in travel times less than 10,000 years. Four factors proved to have a statistically significant impact on reducing travel time to the aquifer: increased induced fracture extent, absence of deep high hydraulic conductivity strata, relatively low fault hydraulic conductivity, and magnitude of overpressure. Modeling suggests that high hydraulic conductivity formations can be more effective barriers to vertical flow than low hydraulic conductivity formations. Furthermore, low hydraulic conductivity faults can result in subsurface pressure compartmentalization, reducing horizontal groundwater flow, and encouraging vertical fluid migration. The modeled worst‐case scenario, using unlikely geology and induced fracture lengths, maximum values for strata hydraulic conductivity and with conservative tracer behavior had a particle travel time of 130 years to the base of the shallow aquifer. This study has identified hydrogeological factors which lead to aquifer vulnerability from shale exploitation.
Evaluation of clinically applied treatment beams with respect to bunker shielding parameters for a Cyberknife M6
Authors: Henzen Dominik , Schmidhalter Daniel , Zanella Claudia Christina , Volken Werner , Mackeprang Paul‐Henry , Malthaner Marco , Fix Michael Karl , Manser Peter
Published: November 2017

Compared to a conventional linear accelerator, the Cyberknife (CK) is a unique system with respect to radiation protection shielding and the variety and number of non‐coplanar beams are two key components regarding this aspect. In this work, a framework to assess the direction distribution and modulation factor (MF) of clinically applied treatment beams of a CyberKnife M6 is developed. Database filtering options allow studying the influence of different parameters such as collimator types, treatment sites or different bunker sizes. A distribution of monitor units (MU) is generated by projecting treatment beams onto the walls, floor and ceiling of the CyberKnife bunker. This distribution is found to be highly heterogeneous and depending, among other parameters, on the bunker size. For our bunker design, 10%–13% of the MUs are delivered to the right and left wall, each. The floor receives more than 64% of the applied MUs, while the wall behind the patient's head is not hit by primary treatment beams. Between 0% and 5% of the total MUs are delivered to the wall at the patient's feet. This number highly depends on the treatment site, e.g., for extracranial patients no beams hit that wall. Collimator choice was found to have minor influence on the distribution of MUs. On the other hand, the MF depends on the collimator type as well as on the treatment site. The MFs (delivered MU/prescribed dose) for all treatments, all MLC treatments, cranial and extracranial treatments are 8.3, 6.4, 7.7, and 9.9 MU/cGy, respectively. The developed framework allows assessing and monitoring important parameters regarding radiation protection of a CK‐M6 using the actually applied treatment beams. Furthermore, it enables evaluating different clinical and constructional situations using the filtering options.
Arthritis After Cancer Immunotherapy: Symptom Duration and Treatment Response
Authors: Smith Melanie H. , Bass Anne R.
Published: November 2017

Objective

Musculoskeletal manifestations of immune‐related adverse events (irAEs) after checkpoint inhibitor immunotherapy for cancer remain incompletely characterized and poorly understood. A recently published case series suggested that immunotherapy‐induced arthritis is an aggressive process requiring high‐dose corticosteroids.

Methods

This was a retrospective chart review of all patients with musculoskeletal irAEs first seen by one of the authors between 2014 and 2016. All patients had been treated for a malignancy with immune checkpoint inhibitors targeting PD‐1 (nivolumab, pembrolizumab), PD‐L1 (durvalumab), and/or CTLA‐4 (ipilimumab, tremelimumab) at Memorial Sloan Kettering Cancer Center.

Results

We identified 10 patients with a mean ± SD age of 63.2 ± 9.7 years. Seven were treated with a combination of checkpoint inhibitors and 3 with nivolumab monotherapy. Four patients developed inflammatory polyarthritis, 4 oligoarthritis, and 2 tenosynovitis. Six were antinuclear antibody positive and 2 had anti–cyclic citrullinated peptide antibodies. Mean ± SD time from the first dose of immunotherapy until joint involvement was 6.3 ± 4.3 months. All 10 patients were treated with systemic corticosteroids, but 6 of 10 required ≤20 mg per day of prednisone. Five patients received steroid‐sparing agents. Mean ± SD time until resolution of joint symptoms after the last dose of immunotherapy was 9.2 ± 6.1 months.

Conclusion

Musculoskeletal irAEs can manifest as a rheumatoid arthritis–like polyarthritis, oligoarthritis, tenosynovitis, or polymyalgia rheumatica. Musculoskeletal symptoms can last more than a year, but they can generally be managed with low to moderate doses of corticosteroids.
Enhancing the Quantum Anomalous Hall Effect by Magnetic Codoping in a Topological Insulator
Authors: Ou Yunbo , Liu Chang , Jiang Gaoyuan , Feng Yang , Zhao Dongyang , Wu Weixiong , Wang Xiao‐Xiao , Li Wei , Song Canli , Wang Li‐Li , Wang Wenbo , Wu Weida , Wang Yayu , He Ke , Ma Xu‐Cun , Xue Qi‐Kun
Published: November 2017

The quantum anomalous Hall (QAH) effect, which has been realized in magnetic topological insulators (TIs), is the key to applications of dissipationless quantum Hall edge states in electronic devices. However, investigations and utilizations of the QAH effect are limited by the ultralow temperatures needed to reach full quantization—usually below 100 mK in either Cr‐ or V‐doped (Bi,Sb)2Te3 of the two experimentally confirmed QAH materials. Here it is shown that by codoping Cr and V magnetic elements in (Bi,Sb)2Te3 TI, the temperature of the QAH effect can be significantly increased such that full quantization is achieved at 300 mK, and zero‐field Hall resistance of 0.97 h/e2 is observed at 1.5 K. A systematic transport study of the codoped (Bi,Sb)2Te3 films with varied Cr/V ratios reveals that magnetic codoping improves the homogeneity of ferromagnetism and modulates the surface band structure. This work demonstrates magnetic codoping to be an effective strategy for achieving high‐temperature QAH effect in TIs.
An Ideal Molecular Sieve for Acetylene Removal from Ethylene with Record Selectivity and Productivity
Authors: Li Bin , Cui Xili , O'Nolan Daniel , Wen Hui‐Min , Jiang Mengdie , Krishna Rajamani , Wu Hui , Lin Rui‐Biao , Chen Yu‐Sheng , Yuan Daqiang , Xing Huabin , Zhou Wei , Ren Qilong , Qian Guodong , Zaworotko Michael J. , Chen Banglin
Published: November 2017

Realization of ideal molecular sieves, in which the larger gas molecules are completely blocked without sacrificing high adsorption capacities of the preferred smaller gas molecules, can significantly reduce energy costs for gas separation and purification and thus facilitate a possible technological transformation from the traditional energy‐intensive cryogenic distillation to the energy‐efficient, adsorbent‐based separation and purification in the future. Although extensive research endeavors are pursued to target ideal molecular sieves among diverse porous materials, over the past several decades, ideal molecular sieves for the separation and purification of light hydrocarbons are rarely realized. Herein, an ideal porous material, SIFSIX‐14‐Cu‐i (also termed as UTSA‐200), is reported with ultrafine tuning of pore size (3.4 Å) to effectively block ethylene (C2H4) molecules but to take up a record‐high amount of acetylene (C2H2, 58 cm3 cm−3 under 0.01 bar and 298 K). The material therefore sets up new benchmarks for both the adsorption capacity and selectivity, and thus provides a record purification capacity for the removal of trace C2H2 from C2H4 with 1.18 mmol g−1 C2H2 uptake capacity from a 1/99 C2H2/C2H4 mixture to produce 99.9999% pure C2H4 (much higher than the acceptable purity of 99.996% for polymer‐grade C2H4), as demonstrated by experimental breakthrough curves.
Copper Catalysis for Nicotinate Synthesis through β‐Alkenylation/Cyclization of Saturated Ketones with β‐Enamino Esters
Authors: Ling Fei , Xiao Lian , Fang Lu , Lv Yaping , Zhong Weihui
Published: November 2017

The first example of a Cu‐catalyzed and 4‐OH‐TEMPO mediated intermolecular [3+3] annulation of saturated ketones with β‐enamino esters is reported herein, which was successfully used for the synthesis of versatile nicotinates through sequential β‐C(sp3)‐H bond alkenylation, enamine‐carbonyl condensation and aromatization. This protocol tolerates a variety of functional groups, thereby providing a practical and efficient method for the fabrication of 5H‐chromeno[4,3‐b]pyridin‐5‐one skeletons.

magnified image
Aqueous‐Containing Precursor Solutions for Efficient Perovskite Solar Cells
Authors: Liu Dianyi , Traverse Christopher J. , Chen Pei , Elinski Mark , Yang Chenchen , Wang Lili , Young Margaret , Lunt Richard R.
Published: November 2017

Perovskite semiconductors have emerged as competitive candidates for photovoltaic applications due to their exceptional optoelectronic properties. However, the impact of moisture instability on perovskite films is still a key challenge for perovskite devices. While substantial effort is focused on preventing moisture interaction during the fabrication process, it is demonstrated that low moisture sensitivity, enhanced crystallization, and high performance can actually be achieved by exposure to high water content (up to 25 vol%) during fabrication with an aqueous‐containing perovskite precursor. The perovskite solar cells fabricated by this aqueous method show good reproducibility of high efficiency with average power conversion efficiency (PCE) of 18.7% and champion PCE of 20.1% under solar simulation. This study shows that water–perovskite interactions do not necessarily negatively impact the perovskite film preparation process even at the highest efficiencies and that exposure to high contents of water can actually enable humidity tolerance during fabrication in air.
Market power in the German dairy value chain
Authors: Grau Aaron , Hockmann Heinrich
Published: November 2017

In this paper, the NEIO approach is extended to allow for oligopsony power in successive markets of a value chain. Two price equations are deduced from simultaneous partial equilibria of the endogenous variables and are embedded in a VECM to account for a long‐run cointegration relationship. The model is estimated via the Kalman–Filter to allow for time variation in the long‐run parameters, and a dynamic factor model used to extract a common factor from the time‐variant coefficients. The results are then used to calculate the industry average input conjectural elasticities. The framework is applied to German dairy value chain data over the time period of January 2000 to March 2011. The results indicate almost perfect competition in the raw milk market and imperfect competition in the dairy output market, which is however far from monopsony. [EconLit citations: L13, D43, C32, Q13].
A Molecular Barium Hydrido Complex Stabilized by a Super‐Bulky Hydrotris(pyrazolyl)borate Ligand
Authors: Shi Xianghui , Hou Cuiping , Zhou Chulu , Song Yanyao , Cheng Jianhua
Published: November 2017

Hydrogenolysis of the scorpionate‐supported barium alkyl complex (TpAd,iPr)Ba[CH(SiMe3)2](THF) (TpAd,iPr=hydrotris(3‐adamantyl‐5‐isopropyl‐pyrazolyl)borate) afforded the dinuclear barium hydrido complex [(TpAd,iPr)Ba(μ‐H)]2 (2), which was characterized by NMR spectroscopy and single‐crystal X‐ray analysis. Exposure of 2 with 1 atm of CO resulted in a reductive coupling process to form the cis‐ethendiolate dianion (3). Reaction of 2 with one equivalent of PhC≡C−C≡CPh gave barium 1,4‐diphenyl‐2‐butyne‐1,4‐diyl complex {[(TpAd,iPr)Ba]2(PhCH−C≡C−CHPh) (4).
Site‐Selective O‐Arylation of Glycosides
Authors: Shang Weidong , Mou Ze‐Dong , Tang Hua , Zhang Xia , Liu Jie , Fu Zhengyan , Niu Dawen
Published: November 2017

Direct and site‐selective O‐arylation of carbohydrates has been a challenge in synthesis. Herein we report a method based on copper‐catalyzed O‐arylation to address this challenge. Proper choice of the ancillary ligand on copper is critical for the efficiency and site selectivity of this transformation. This method features mild conditions, tolerates various functional groups, and demonstrates broad substrate scope.
Living Ab Initio Emulsion Polymerization of Methyl Methacrylate in Water Using a Water‐Soluble Organotellurium Chain Transfer Agent under Thermal and Photochemical Conditions
Authors: Fan Weijia , Tosaka Masatoshi , Yamago Shigeru , Cunningham Michael F.
Published: November 2017

Ab initio emulsion polymerization of methyl methacrylate (MMA) using a water‐soluble organotellurium chain transfer agent in the presence of the surfactant Brij 98 in water is reported. Polymerization proceeded under both thermal and visible light‐irradiation conditions, giving poly(methyl methacrylate) (PMMA) with controlled molecular weight and low dispersity (Đ<1.5). Despite the formation of an opaque latex, the photoactivation of the organotellurium dormant species took place efficiently, as demonstrated by the quantitative monomer conversion and temporal control. Control of polymer particle size (PDI<0.030) was also achieved using a semi‐batch monomer addition process. The PMMA polymer in the particles retained high end‐group fidelity and was successfully used for the synthesis of block copolymers.
The Divergent Dimerization Behavior of N‐Substituted Dicyanomethyl Radicals: Dynamically Stabilized versus Stable Radicals
Authors: Okino Kohei , Hira Shota , Inoue Yuki , Sakamaki Daisuke , Seki Shu
Published: November 2017

Herein, we demonstrate that the dimerization behavior of amine‐substituted dicyanomethyl radicals can be switched from σ‐ to π‐dimerization simply by varying the electron‐donating substituents. For dicyanomethyl radicals with a 4,4′‐ditolylamine (DT.) or a phenothiazine (PT.) substituent, the monomeric radical form and the corresponding dimer connected by a reversible C−C bond (σ‐dimer) are in equilibrium in solution. On the other hand, the radical with the julolidine skeleton (JD.) does not undergo σ‐dimerization and was isolated as a stable radical in spite of the absence of bulky protecting groups. X‐ray single‐crystal analysis revealed that JD. forms the π‐dimer in the crystalline state, and variable‐temperature spectroscopy showed that JD. is in equilibrium with the π‐dimer in toluene solution. DFT calculations point to the importance of electrostatic interactions as a driving force for the π‐dimerization of JD. because of its polarized structure.
A novel ultra‐low energy reverse osmosis membrane modified by chitosan with glutaraldehyde crosslinking
Authors: Mehta Bhargav B. , Joshi Rutvik N. , Raval Hiren D.
Published: November 2017

The energy consumption of reverse osmosis (RO) has declined significantly since inception and to further decrease the energy consumption is a challenging task. The present article demonstrates the novel method to increase the membrane productivity and reduce energy consumption of desalination. Thin film composite RO (TFC RO) membrane was subjected to 2000 mg/L sodium hypochlorite for 1 h followed by varying concentrations of chitosan and glutaraldehyde for 1 h each to make a hydrophilic supra‐molecular assembly of linear polysaccharide over the polyamide layer. RO membrane exposed to 1000 mg/L chitosan and glutaraldehyde each reported 180% increase in water‐flux with about 2.7% increase in divalent ion rejection as compared to virgin TFC RO membrane. The superior performance of the membrane was explained by increased hydrophilicity as shown by decline in contact angle from 46.37° to 29.87°, increase in surface area ratio from atomic force microscope image analysis, and modification in chemical structure of polyamide from attenuated total reflectance Fourier transform infrared spectroscopy. It was further investigated that curing of glutaraldehyde treated membrane resulted in decreased water‐flux because of increase in crosslink density. Thus, an ultra‐low energy RO process can be developed based on polyamide–chitosan–glutaraldehyde membrane. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45971.
IEI‐EMF provocation case studies: A novel approach to testing sensitive individuals
Authors: Verrender Adam , Loughran Sarah P. , Anderson Vitas , Hillert Lena , Rubin G. James , Oftedal Gunnhild , Croft Rodney J.
Published: November 2017

The etiology of Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI‐EMF) is controversial. While the majority of studies have indicated that there is no relationship between EMF exposure and symptoms reported by IEI‐EMF sufferers, concerns about methodological issues have been raised. Addressing these concerns, the present experiment was designed as a series of individual case studies to determine whether there is a relationship between radiofrequency‐electromagnetic field (RF‐EMF) exposure and an IEI‐EMF individual's self‐reported symptoms. Three participants aged 44–64 were tested during a series of sham and active exposure trials (2 open‐label trials; 12 randomized, double‐blind, counterbalanced trials), where symptom severity and exposure detection were scored using 100 mm visual analogue scales. The RF‐EMF exposure was a 902–928 MHz spread spectrum digitally modulated signal with an average radiated power output of 1 W (0.3 W/m2 incident power density at the participant). In the double‐blind trials, no significant difference in symptom severity or exposure detection was found for any of the participants between the two conditions. Belief of exposure strongly predicted symptom severity score for all participants. Despite accounting for several possible limitations, the present experiment failed to show a relationship between RF‐EMF exposure and an IEI‐EMF individual's symptoms. Bioelectromagnetics. 39:132–143, 2018. © 2017 Wiley Periodicals, Inc.
Utility of Cremophor RH 40 as a micellar improvement for spectrofluorimetric estimation of sorafenib in pure form, commercial preparation, and human plasma
Authors: Zidan Dalia W. , Elmasry Manal S. , Hassan Wafaa S. , Shalaby Abdalla A.
Published: November 2017

An easy, quick, simple and accurate spectrofluorimetric method was recognized and validated for evaluation of sorafenib (SOR) in pure form and biologically in plasma. Cremophor RH 40 (Cr RH 40) used for enhancing the fluorescence activity of SOR in phosphate buffer (pH 7). Cr RH 40 improved the native fluorescence of SOR remarkably in water. The fluorescence spectrum of SOR was observed at 405 nm after excitation at 265 nm. The linearity appeared to be in the range of 5 to 600 ng ml−1 for pure and from 9 to 500 ng ml−1 for plasma using the protein precipitation (ppt) method while from 10 to 500 ng ml−1 for plasma using liquid–liquid extraction method. The precisions and the accuracy of the estimated method gave satisfactory results. The recommended method was effectively applied for determination of SOR in human plasma with high recovery values. The results of some compounds that are possibly found in plasma were studied. The proposed method was also focused on real volunteers and a drug dissolution test.
Pichia pastoris Alcohol Oxidase 1 (AOX1) Core Promoter Engineering by High Resolution Systematic Mutagenesis
Authors: Portela Rui M. C. , Vogl Thomas , Ebner Katharina , Oliveira Rui , Glieder Anton
Published: November 2017

Unravelling the core promoter sequence‐function relationship is fundamental for engineering transcription initiation and thereby a feasible “tuning knob” for fine‐tuning expression in synthetic biology and metabolic engineering applications. Here a systematic replacement studies of the core promoter and 5′ untranslated region (5′UTR) of the exceptionally strong and tightly methanol regulated Komagataella phaffii (syn. Pichia pastoris) alcohol oxidase 1 (AOX1) promoter at unprecedented resolution is performed. Adjacent triplets of the 200 bp long core promoter are mutated at a time by changing the wild‐type sequence into cytosine or adenine triplets, resulting in 130 variants that are cloned upstream of an eGFP reporter gene providing a library for expression fine‐tuning. Mutations in the TATA box motif, regions downstream of the transcription start site or next to the start codon in the 5′UTR had a significant effect on the eGFP fluorescence. Surprisingly, mutations in most other regions are tolerated, indicating that yeast core promoters can show a high tolerance toward small mutations, supporting regulatory models of degenerate motifs, or redundant design. The authors exploited these neutral core promoter positions, not affecting expression, to introduce extrinsic sequence elements such as cloning sites (allowing targeted core promoter/5′UTR modifications) and bacterial promoters (applicable in multi host vectors).
Baicalein Reduces Oxidative Stress in CHO Cell Cultures and Improves Recombinant Antibody Productivity
Authors: Ha Tae Kwang , Hansen Anders Holmgaard , Kol Stefan , Kildegaard Helene Faustrup , Lee Gyun Min
Published: November 2017

Oxidative stress that naturally accumulates in the endoplasmic reticulum (ER) as a result of mitochondrial energy metabolism and protein synthesis can disturb the ER function. Because ER have a responsibility on the protein synthesis and quality control of the secreted proteins, ER homeostasis has to be well maintained. When H2O2, an oxidative stress inducer, is added to recombinant Chinese hamster ovary (rCHO) cell cultures, it reduced cell growth, monoclonal antibody (mAb) production, and galactosylated form of mAb in a dose‐dependent manner. To find an effective antioxidant for rCHO cell cultures, six antioxidants (hydroxyanisole, N‐acetylcysteine, baicalein, berberine chloride, kaempferol, and apigenin) with various concentrations are examined individually as chemical additives to rCHO cell cultures producing mAb. Among these antioxidants, baicalein shows the best mAb production performance. Addition of baicalein significantly reduced the expression level of BiP and CHOP along with reduced reactive oxygen species level, suggesting oxidative stress accumulated in the cells can be relieved using baicalein. As a result, addition of baicalein in batch cultures resulted in 1.7–1.8‐fold increase in the maximum mAb concentration (MMC), while maintaining the galactosylation of mAb. Likewise, addition of baicalein in fed‐batch culture resulted in 1.6‐fold increase in the MMC while maintaining the galactosylation of mAb. Taken together, the results obtained here demonstrate that baicalein is an effective antioxidant to increase mAb production in rCHO cells.
Library of Norcoclaurine Synthases and Their Immobilization for Biocatalytic Transformations
Authors: Lechner Horst , Soriano Pablo , Poschner Roman , Hailes Helen C. , Ward John M. , Kroutil Wolfgang
Published: November 2017

Norcoclaurine synthases (NCS), catalyzing a Pictet–Spengler reaction in plants as one of the first enzymes in the biosynthetic benzylisoquinoline pathway, are investigated for biocatalytic transformations. The library of NCS available is extended by two novel NCSs from Argemone mexicana (AmNCS1, AmNCS2) and one new NCS from Corydalis saxicola (CsNCS); furthermore, it is shown that the NCS from Papaver bracteatum (PbNCS) is a highly productive catalyst leading to the isoquinoline product with up to >99% e.e. Under certain conditions lyophilized whole Escherichia coli cells containing the various overexpressed NCS turned out to be suitable catalysts. The reaction using dopamine as substrate bears several challenges such as the spontaneous non‐stereoselective background reaction and side reactions. The PbNCS enzyme is successfully immobilized on various carriers whereby EziG3 proved to be the best suited for biotransformations. Dopamine showed limited stability in solution resulting in the coating of the catalyst over time, which could be solved by the addition of ascorbic acid (e.g., 1 mg ml−1) as antioxidant.
Supplier Development Practices for Sustainability: A Multi‐Stakeholder Perspective
Authors: Liu Lingxuan , Zhang Min , Hendry Linda C. , Bu Maoliang , Wang Shi
Published: November 2017

Supplier development for sustainability is a critical element of sustainable supply chain management and requires extensive multi‐stakeholder collaboration. This article establishes a conceptual four‐stage framework to analyse the collaborative mechanisms of supplier development practices, and presents an exploratory, qualitative analysis to identify the major contributors of sustainable supplier development practices, such as NGOs, industrial associations, consulting firms etc. Based on semi‐structured interviews about 63 organizations from different regions and industries, this article identifies three types of contributor: drivers, facilitators and inspectors. Instead of traditional stakeholder engagement processes, these contributors actively collaborate with buying firms and suppliers to design, implement and evaluate sustainable supplier development programs. The article then provides a matrix to describe the supply chain coverage and supplier performance of supplier development practices, given the absence or positive involvement of facilitators and inspectors. We conclude our study by suggesting future research directions as well as discussing managerial implications. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
A computer game for teaching and learning algebra topics at undergraduate level
Authors: García Ivan , Cano Edgar
Published: November 2017

Technology is increasingly changing the way that engineering students are taught. In recent years, we have witnessed a significant growth in using computer game technologies for teaching and learning in different engineering fields and contexts. This approach offers the ability to create complex and highly interactive scenarios with a solid theoretical basis to teach material in new and highly interactive ways. This paper introduces the application of the game‐based learning approach and instructional design for creating a 2D computer game in order to support mathematics teaching and learning in the first‐year of an undergraduate engineering course. Additionally, an experiment was conducted on a Computer and Electronic Engineering course to evaluate the effects of the proposed game by following the “competency‐based learning” approach on students with sequential and global learning styles. The results showed that the computer game increased the learning experience and motivation of global learners when learning mathematical topics.