bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Cariogenic and Erosive Potential of Some Beverages Consumed in Enugu Metropolis, South East Nigeria
Authors: Maduakor C. Uzoamaka , Onyemelukwe F. Ngozi , Okonkwo N. Innocent , Azubuike C. Nkiruka , Ogu O. Cornelius , Chukwu I. Paul John , Maduakor N. Sam
Published: April 2020

Dental caries is a global infectious disease and the most common oral cavity disease. Among the theories which explain caries is the activity of acids produced by bacteria resulting from dietary fermentation of carbohydrates (sugars). Modernization has led to change in our diet and life style and the beverage industries are having a field day. Though people are aware of the harm caused by these beverages and fruit juices on the dental hard tissues, they still choose to guzzle them. The study was an in vitro analysis of cariogenic and erosive potential of different beverages mostly consumed in Enugu metropolis, South Nigeria. Seventeen samples were analyzed physically and chemically using the following parameters, pH, titratable acidity (TA), total soluble solid content (TSSC), reducing sugars (RS), non-reducing sugars (NRS) and total sugars (TS). Standard analytical techniques were used including potentiometry for endogenous pH, Association of Official Analytical Chemists approved method for titratable acidity, Brix refractometry using Abbe refractometer for TSSC and Fehling’s method for sugars. Coke pressented the highest pH (2.83) followed by La casara 2.92 and the least was Bobo strawberry 4.6. California and Holladia recorded the least and highest TA values of 0.04% and 0.26% respectively. Bobo strawberry had the least TSSC (6.81oBrix) and the highest was Hollandia yogurt (16.34oBrix). Seven Up presented the highest reducing sugar 20.45g/100ml. Mirinda and Bobo strawberry had the highest total sugars 68.90g/100ml each. For non-reducing sugars, the values ranged from 0g/100ml (Chivita apple) to 65.45g/100ml (Bobo strawberry). There were significant differences among the samples for reducing sugars (P<0.05). These beverages showed low endogenous pH that were below the critical value for enamel demineralization (pH<5.5). They are potentially hazardous to the teeth and should not be consumed regularly because of their low pH and high sugar content.
Assessment of Soil Organic Carbon Stock under Different Density Classes of Oak (Quercus leucotricophora) Forests in Uttarakhand, India
Authors: Soni Antrix , Bhatt Parul , Devi Usha
Published: April 2020

Soil organic carbon (SOC) is one of the most important and essential constituents of soil. It is the largest reservoir of terrestrial carbon. Here, an investigation was carried for the assessment of Soil Organic Carbon in three different density classes of Oak forest of Chakrata (Distt. Dehradun), Itarna (Distt. Tehri Garhwal) and Lansdowne (Distt. Pauri Garhwal) forest divisions of Uttarakhand. Three soil samples from each forest system at 0-30 cm depth were collected from each density to assess soil organic carbon stock. A total of 81 soil sample were collected in three seasons. In summer season among all three division maximum Soil Organic Carbon was assessed in Chakrata dense forest division (81.65 t ha-1), followed by moderate forest (47.66 t ha-1) and open forest (37.68 t ha-1) of Chakrata forest division. In Lansdowne forest division maximum SOC was found in dense forest (79.82 t ha-1) followed by moderate (48.53 t ha-1) and open forest (35.37 t ha-1) respectively. A similar trend was reported in case of Itarna forest division. Where (78.47 t ha-1) come up to maximum reservoir of SOC followed by moderate forest (46.50 t ha-1) and open forest (34.52 t ha-1) respectively. In rainy season among all three division maximum Soil Organic Carbon was assessed in Chakrata dense forest division (66.24 t ha-1), followed by moderate forest(45.62 t ha-1) and open forest (29.53 t ha-1) of Chakrata forest division. In Lansdowne forest division maximum SOC was found in dense forest (75.48 t ha-1) followed by moderate 48.65 t ha-1) and open forest (22.36 t ha-1) respectively. Similar trend was reported in case of Itarna forest division.In winter season among all three divisions maximum Soil Organic Carbon was assessed in Chakrata dense forest division (81.89 t ha-1), followed by moderate forest (56.62 t ha-1) and open forest (32.32 t ha-1) of Chakrata forest division. In Lansdowne forest division maximum SOC was found in dense forest (81.90 t ha-1) followed by moderate (57.43 t ha-1) and open forest (35.99 t ha-1) respectively. A similar trend was reported in case of Itarna forest division. This study reveals that in the Soil Organic Carbon is maximum in the dense forest followed by moderate and open forest which could be possibly due the more flora and fauna in the dense forest followed by moderate and open forest. Possibly the activities of flora and fauna lead to the addition of more carbon content in the soil. The study demonstrated similar trends of SOC in three different dense, moderate and open density classes of Oak forest. These outcomes of the study may explore the possibility to improve the scientific basis of forest management and land use in the near future.
Comparative Effects of Aqueous Leaf Extracts of Thymus schimperi and Moringa stenopetala on Regional Blood Flow Velocity and Vascular Resistance of Pre-eclampsia Rat Models
Authors: Mergiaw Kumlachew , Mengesha Yoseph A. , Makonnen Eyasu , Tolessa Tesfaye , Genet Solomon , Abebe Abiy , Tadele Ashenif , Gebreyesus Kidist , Ashencho Demeke , Debella Asfaw
Published: April 2020

Background: Pre-eclampsia (PE) is a common hypertensive disorder of pregnancy with a prevalence rate of 3-5%. There is no modern drug which cures PE so far. On the other hand, plant medicines are claimed to cure this disease. Exploring potential plant medicines for their therapeutic and/or prophylactic uses in this disease, therefore has paramount importance. In Ethiopia, there is a strong claim that leaves of Moringa stenopetala and Thymus schimperi have anti-hypertension activities. Thus, the current study was supposed to prove the potential therapeutic effects of the two plants against PE. PE reduces organ blood flow and increasesvascular resistance. Assessing these variables has widely been accepted when monitoring high-risk pregnancies and evaluating therapeutic and/or prophylactic uses of drugs.

Methods: A comparative experimental case control study was employed to determine the effects of aqueous crude extracts of Thymus schimperi and Moringa stenopetala on regional blood flow velocities and vascular resistance of PE Albino-Wistar rat models induced by a potent vasoconstrictor, nitro-arginine methyl ester(L-NAME). A Doppler flow meter (Atys, Directive 93/42/EEC/CEE, Model, BASIC123LP) was used to measure the systolic and diastolic regional blood flow velocities through abdominal aorta, uterine, renal and common carotid arteries.  The peripheral vascular resistance for the respective vessels were evaluated using resistivity and pulsatility indices.

Results: Aqueous leaf extracts of T. schimperi (ALETS) and M. stenopetala (ALEMS) significantly increased regional blood flow velocities and decreased peripheral vascular resistance in PE rat modelsin a dose dependent pattern compared with untreated controls. For example, ALETS treated PE groups showed increased diastolic blood velocity (DBV) (cm/sec) of uterine arteries 3.8±0.4 (p<0.05), 4.2±0.4 (p<0.01), 7.3±0.5 (p<0.01), while ALEMS treated PE group had uterine arterial DBV of 2.8±0.3 (p<0.01), 3.5±0.8 (p<0.05), 6.6±0.8 (p<0.01) with daily doses of 250 mg/kg, 500 mg/kg and 1 gm/kg, respectively. Moreover, the vascular resistances (measured by resistivity and pulsatility indices), of the respective vessels were significantly lower in a dose dependent pattern.

Conclusion: Both ALETS and ALEMS could increaseregional blood flow velocities and decrease vascular resistances of PE rat models. Further investigation should, however, be carried out to confirm their therapeutic merits.
Comparison of Regression Model Concepts for Estimating Traffic Noise
Authors: Emeka Amah, Victor , Tam-Jones Atuboyedia,
Published: April 2020

Traffic noise at two locations which are Rumuokoro and Rumuola in Port Harcourt city, Rivers state Nigeria was studied. The study was done for 3 days at each location. Variables such as atmospheric parameters and traffic density were measured along with the noise measurement. The atmospheric parameters measured were temperature, relative humidity and wind speed. Traffic density includes number of small cars and trucks per 20m radius. Three empirical model concepts were proposed, calibrated using multiple regression analysis and validated by cross validation and coefficient of determination (R2). The models are a linear model, a polynomial model and an exponential model. The coefficient of determination for the linear model ranged from 0.25 to 0.94 at Rumuokoro and 0.29 to 0.86 at Rumuola. The coefficient of correlation for the polynomial model ranged from 0.062 to 0.998 at Rumuokoro and 0.05 to 0.998 at Rumuola. The coefficient of correlation for the exponential model ranged from 0.28 to 0.92 at Rumuokoro and 0.45 to 0.89 at Rumuola. The exponential model was concluded to be the best model concept because of its performance in predicting noise levels using data from other days with moderately high and consistent coefficient of determination at both locations. However, if extrapolation is not to be considered, the polynomial model concept is very useful.
Analysis of nutrients and compounds potentially reducing risks of overweightness and obesity-related diseases in raw and roasted Adenanthera pavonina seeds from Samoa
Authors: Huml Lukas , Drabek Ondrej , Pohorela Barbora , Kotikova Zora , Umar Mohammed , Miksatkova Petra , Kokoska Ladislav
Published: April 2020

Recently, Samoans have faced to alarming increase in the prevalence of obesity related diseases, which are connected to the consumption of imported calorie-rich and nutrient-poor food products. It is believed that the re-introduction of native diet may mitigate these negative trends. In Samoa, the seeds of Adenanthera pavonina, an underutilized leguminous tree, are popularly eaten when roasted. Although the seeds are also used in traditional medicine to treat inflammatory and cardiovascular diseases, information on their nutrients and any compounds potentially reducing risks of related health disorders is very limited. Therefore, the objective of this study was to analyse the nutrients and compounds potentially reducing risks of overweight- and obesity-related health problems in raw and roasted A. pavonina seeds from Samoa. The standard analytical and microbiological methods, namely gas chromatography–mass spectrometry, inductively coupled plasma optical emission spectrometry, high-performance liquid chromatography with fluorescence detection, ultrahigh-performance liquid chromatography-tandem mass spectrometry, and Czech technical standard methods, were used for the determination of fatty acids, minerals, tocopherols, phenolic compounds, and B vitamins, respectively. The analyses showed that the lignoceric (17.59% and 18.24%), linoleic (39.80% and 37.88%), and oleic acids (14.67% and 14.75%) were the most abundant in the oil of raw and roasted seeds, with the unsaturated forms present in higher amounts than saturated. The seeds were found to be rich of vitamin E (33.09 and 15.94 mg/100 g), whereas the contents of vitamins B1, B2, B3, and B6 were rather low. Calcium, magnesium, phosphorus, potassium, and sulphur were the minerals found in the highest concentrations. Salicylic acid (201.01 and 151.95 µg/100 g) has been detected in higher amounts than other phenolic compounds. In summary, the findings of this study indicate that the both raw and roasted seeds of A. pavonina are good sources of various health-beneficial nutrients, including those reducing the negative effects of obesity.
Evaluation of coffee pulp as substrate for polygalacturonase production in solid state fermentation
Authors: Frómeta Rosa Amarilis Rodríguez , Sánchez José Laencina , García José María Ros
Published: April 2020

The purpose of this research is to evaluate the coffee pulp, a by-product of coffee processing, as substrate for polygalacturonase production by solid state fermentation. In addition, it is a way to take advantage of the coffee pulp. Characterization of the coffee pulp revealed a high content of nutrients for fungi growth, such as reducing sugars (5.4% of dry pulp), proteins (9.4% of dry pulp), pectins (20.5% of dry pulp), which are inducers of pectic hydrolases production and source of carbon after degradation, and caffeine (1.4% of dry pulp), among others. The characterization of the cell-wall of coffee pulp revealed, after polysaccharides fractionation, the content in cell-wall pectins (25.5%), hemicelluloses (11.5%) and cellulosic residue (44%). A strain of Aspergillus niger, called van Thiegem, has been selected as a good producer of polygalacturonases (60 U/ml) using the coffee pulp as the growth substrate. During fermentation, reducing sugars, caffeine and phenolic compounds were consumed till almost exhaustion. A partial characterization of the polygalacturonase using high methoxyl pectin as substrate indicates an optimal pH of 4.0 and 45oC as optimal temperature, which are good values for the use of the enzyme in vegetable processing, including coffee processing.
Fat substitution by inulin in goat milk ice cream produced with cajá (Spondias mombin) pulp and probiotic cultures: influence on composition, texture, and acceptability among consumers of two Brazilian regions
Authors: De Paula Clara Mítia , Dos Santos Karina Maria Obrich , Oliveira Leandro Silva , Silva Oliveira Jacqueline da , Buriti Flávia Carolina Alonso , Saad Susana Marta Isay
Published: April 2020

The production of a goat milk ice cream with a typical Brazilian fruit, probiotic cultures and with the fat substitution by inulin could be an opportunity of products’ diversification for the growing goat dairy sector in Brazil and also to attend the consumers’ demand of healthy indulgence products. However, the probiotic stability and texture could be affected by the fat replacement in a frozen product, and sensory acceptability can vary according to the country region. The objective of this study was to investigate the effect of substitution of goat milk cream by inulin on the stability and quality parameters such as fat content, fatty acid profile, lactobacilli viability, hardness and melting rate of goat milk ice cream produced with cajá pulp and probiotic cultures of Lactobacillus rhamnosus or Lactobacillus paracasei. Focusing on the opportunity of spreading food products containing regional ingredients, a sensory evaluation was conducted with consumers of two distinct Brazilian regions (São Paulo and Sobral, south-eastern and north-eastern cities, respectively). Formulations with inulin fitted requirements for low fat and low saturated fat products. Probiotic cultures survived well in all tested formulations since added probiotics maintained viability levels above 8.00 log cfu/g during storage. The full-fat ice creams achieved significant higher acceptability among the consumers of Sobral when compared with those of São Paulo, reinforcing that familiarization with goat milk can influence the acceptability of caprine dairy products. Inulin added ice creams showed lower overrun, with hardness and melt-down profile increased in comparison with milk cream formulations. Nonetheless, inulin successfully substituted milk cream in goat milk ice creams with cajá as their scores of sensory acceptability were above 7.00 and similar within both consumer groups. The multi-functional character of the inulin added ice creams indicate their potential contribution for good health if consumed as part of a well-balanced diet.
CANT1 deficiency in a mouse model of Desbuquois dysplasia impairs glycosaminoglycan synthesis and chondrocyte differentiation in growth plate cartilage
Authors: Kodama Kazuki , Takahashi Hiroaki , Oiji Nobuyasu , Nakano Kenta , Okamura Tadashi , Niimi Kimie , Takahashi Eiki , Guo Long , Ikegawa Shiro , Furuichi Tatsuya
Published: April 2020

Desbuquois dysplasia (DD) type 1 is a rare skeletal dysplasia characterized by a short stature, round face, progressive scoliosis, and joint laxity. The causative gene has been identified as calcium‐activated nucleotidase 1 (CANT1), which encodes a nucleotidase that preferentially hydrolyzes UDP to UMP and phosphate. In this study, we generated Cant1 KO mice using CRISPR/Cas9‐mediated genome editing. All F0 mice possessing frameshift deletions at both Cant1 alleles exhibited a dwarf phenotype. Germline transmission of the edited allele was confirmed in an F0 heterozygous mouse, and KO mice were generated by crossing of the heterozygous breeding pairs. Cant1 KO mice exhibited skeletal defects, including short stature, thoracic kyphosis, and delta phalanx, all of which are observed in DD type 1 patients. The glycosaminoglycan (GAG) content and extracellular matrix space were reduced in the growth plate cartilage of mutants, and proliferating chondrocytes lost their typical flat shape and became round. Chondrocyte differentiation, especially terminal differentiation to hypertrophic chondrocytes, was impaired in Cant1 KO mice. These findings indicate that CANT1 is involved in the synthesis of GAG and regulation of chondrocyte differentiation in the cartilage and contribute to a better understanding of the pathogenesis of DD type 1.
Automated quality control in nuclear medicine using the structured noise index
Authors: Nelson Jeffrey S. , Samei Ehsan
Published: April 2020

Purpose

Daily flood‐field uniformity evaluation serves as the central element of nuclear medicine (NM) quality control (QC) programs. Uniformity images are traditionally analyzed using pixel value‐based metrics, that is, integral uniformity (IU), which often fail to capture subtle structure and patterns caused by changes in gamma camera performance, requiring visual inspections which are subjective and time demanding. The goal of this project was to implement an advanced QC metrology for NM to effectively identify nonuniformity issues, and report issues in a timely manner for efficient correction prior to clinical use. The project involved the implementation of the program over a 2‐year period at a multisite major medical institution.

Methods

Using a previously developed quantitative uniformity analysis metric, the structured noise index (SNI) [Nelson et al. (2014), \textit{J Nucl Med.}, \textbf{55}:169—174], an automated QC process was developed to analyze, archive, and report on daily NM QC uniformity images. Clinical implementation of the newly developed program ran in parallel with the manufacturer’s reported IU‐based QC program. The effectiveness of the SNI program was evaluated over a 21‐month period using sensitivity and coefficient of variation statistics.

Results

A total of 7365 uniformity QC images were analyzed. Lower level SNI alerts were generated in 12.5% of images and upper level alerts in 1.7%. Intervention due to image quality issues occurred on 26 instances; the SNI metric identified 24, while the IU metric identified eight. The SNI metric reported five upper level alerts where no clinical engineering intervention was deemed necessary.

Conclusion

An SNI‐based QC program provides a robust quantification of the performance of gamma camera uniformity. It operates seamlessly across a fleet of multiple camera models and, additionally, provides effective workflow among the clinical staff. The reliability of this process could eliminate the need for visual inspection of each image, saving valuable time, while enabling quantitative analysis of inter‐ and intrasystem performance.
The effect of stereotactic body radiotherapy (SBRT) using flattening filter‐free beams on cardiac implantable electronic devices (CIEDs) in clinical situations
Authors: Aslian Hossein , Kron Tomas , Watts Troy , Akalanli Cagla , Hardcastle Nicholas , Lonski Peta , Montaseri Atousa , Hay Barry , Korte James , Berk Kemal , Longo Francesco , Severgnini Mara
Published: April 2020

Purpose

This study focused on determining risks from stereotactic radiotherapy using flattening filter‐free (FFF) beams for patients with cardiac implantable electronic device (CIEDs). Two strategies were employed: a) a retrospective analysis of patients with CIEDs who underwent stereotactic radiosurgery (SRS)/SBRT at the Peter MacCallum Cancer Centre between 2014 and 2018 and b) an experimental study on the impact of FFF beams on CIEDs.

Methods

A retrospective review was performed. Subsequently, a phantom study was performed using 30 fully functional explanted CIEDs from two different manufacturers. Irradiation was carried out in a slab phantom with 6‐MV and 10‐MV FFF beams. First, a repetition‐rate test (RRT) with a range of beam pulse frequencies was conducted. Then, multifraction SBRT (48 Gy/4 Fx) and single‐fraction SBRT (28 Gy/1 Fx) treatment plans were used for lung tumors delivered to the phantom.

Results

Between 2014 and 2018, 13 cases were treated with an FFF beam (6 MV, 1400 MU/min or 10 MV, 2400 MU/min), and 15 cases were treated with a flattening filter (FF) beam (6 MV, 600 MU/min). All the devices were positioned outside the treatment field at a distance of more than 5 cm, except for one case, and no failures were reported due to SBRT/SRS. In the phantom rep‐rate tests, inappropriate sensing occurred, starting at a rep‐rate of 1200 MU/min. Cardiac implantable electronic device anomalies during and after delivering VMAT‐SBRT with a 10‐MV FFF beam were observed.

Conclusions

The study showed that caution should be paid to managing CIED patients when they undergo SBRT using FFF beams, as it is recommended by AAPM TG‐203. Correspondingly, it was found that for FFF beams although there is small risk from dose‐rate effects, delivering high dose of radiation with beam energy greater than 6 MV and high‐dose rate to CIEDs positioned in close vicinity of the PTV may present issues.
“Tell me more about this…”: An examination of the efficacy of follow‐up open questions following an initial account
Authors: Kontogianni Feni , Hope Lorraine , Taylor Paul J. , Vrij Aldert , Gabbert Fiona
Published: April 2020

In information gathering interviews, follow‐up questions are asked to clarify and extend initial witness accounts. Across two experiments, we examined the efficacy of open‐ended questions following an account about a multi‐perpetrator event. In Experiment 1, 50 mock‐witnesses used the timeline technique or a free recall format to provide an initial account. Although follow‐up questions elicited new information (18–22% of the total output) across conditions, the response accuracy (60%) was significantly lower than that of the initial account (83%). In Experiment 2 (N = 60), half of the participants received pre‐questioning instructions to monitor accuracy when responding to follow‐up questions. New information was reported (21–22% of the total output) across conditions, but despite using pre‐questioning instructions, response accuracy (75%) was again lower than the spontaneously reported information (87.5%). Follow‐up open‐ended questions prompt additional reporting; however, practitioners should be cautious to corroborate the accuracy of new reported details.
Relationship Between Pain and Sedentary Behavior in Rheumatoid Arthritis Patients: A Cross‐Sectional Study
Authors: O’Leary Helen , Larkin Louise , Murphy Gráinne M. , Quinn Karen
Published: April 2020

Objective

Despite the known benefits of physical activity, high numbers of individuals with rheumatoid arthritis (RA) remain physically inactive and sedentary. Little is known about the determinants of sedentary behavior (SB) in RA. This cross‐sectional study was undertaken to examine a range of pain characteristics and RA‐related symptoms and their relationship with objectively measured SB.

Methods

In total, 76 adults with RA wore an activPAL4 accelerometer (PAL Technologies) over a 7‐day period. Pain characteristics (pain intensity, painful joint count, nonarticular pain), fatigue, sleep, depression, anxiety, and disease activity were assessed. Analyses were first conducted to evaluate correlations with sedentary time. The independent contribution of pain characteristics to variation in SB was analyzed with multivariable linear regression (adjusted for demographic data and disease activity).

Results

Participants with valid accelerometer data (n = 72) spent a mean ± SD of 533.7 ± 100.1 minutes/day in SB. Positive associations with daily SB were found for pain intensity (r = 0.31, P < 0.01) and number of painful joints (r = 0.24, P < 0.05) but not nonarticular pain. In multivariable analyses, pain characteristics were not independently associated with SB. Analyses indicated that disease activity had an indirect association with SB mediated by pain intensity. Other correlates of daily SB included anxiety and depression but not fatigue or sleep.

Conclusion

Results suggest that while pain and other RA‐related factors do play a role in SB, they do not appear to have a significant influence after accounting for other variables. Future research should investigate SB and the role of factors unrelated to the symptoms of RA.
Measuring Advanced/Extended Practice Roles in Arthritis and Musculoskeletal Care in Canada
Authors: Lundon Katie , Inrig Taucha , Paton Morag , Shupak Rachel , Kennedy Carol , McGlynn Mandy , Barber Claire
Published: April 2020

Objective

Our objective was to characterize Canadian workforce attributes of extended role practitioners (ERPs) in arthritis care.

Methods

We used an exploratory, mixed‐methods study that was based on the Canadian Rheumatology Association's Stand Up and Be Counted Rheumatologist Workforce Survey (2015). An anonymous online survey was deployed to groups of non‐physician health care professionals across Canada who potentially had post‐licensure training in arthritis care. Demographic and practice information were elicited. Qualitative responses were analyzed using grounded theory techniques.

Results

Of 141 respondents, 91 identified as practicing in extended role capacities. The mean age of ERP respondents was 48.7; 87% were female, and 41% of ERPs planned to retire within 5 to 10 years. Respondents were largely physical or occupational therapists by profession and practiced in urban/academic (46%), community (39%), and rural settings (13%). Differences in practice patterns were noted between ERPs (64.5%) and non‐ERPs (34.5%), with more ERPs working in extended role capacities while retaining activities reflective of their professional backgrounds. Most respondents (95%) agreed that formal training is necessary to work as an ERP, but only half perceived they had sufficient training opportunities. Barriers to pursuing training were varied, including personal barriers, geographic barriers, patient‐care needs, and financial/remuneration concerns.

Conclusion

To our knowledge, no previous studies have assessed the workforce capacity or the perceived need for the training of ERPs working in arthritis and musculoskeletal care. Measurement is important because in these health disciplines, practitioners’ scopes of practice evolve, and ERPs integrate into the Canadian health care system. ERPs have emerged to augment provision of arthritis care, but funding for continuing professional development opportunities and for role implementation remains tenuous.
A Droplet Microfluidic System to Fabricate Hybrid Capsules Enabling Stem Cell Organoid Engineering
Authors: Liu Haitao , Wang Yaqing , Wang Hui , Zhao Mengqian , Tao Tingting , Zhang Xu , Qin Jianhua
Published: April 2020

Organoids derived from self‐organizing stem cells represent a major technological breakthrough with the potential to revolutionize biomedical research. However, building high‐fidelity organoids in a reproducible and high‐throughput manner remains challenging. Here, a droplet microfluidic system is developed for controllable fabrication of hybrid hydrogel capsules, which allows for massive 3D culture and formation of functional and uniform islet organoids derived from human‐induced pluripotent stem cells (hiPSCs). In this all‐in‐water microfluidic system, an array of droplets is utilized as templates for one‐step fabrication of binary capsules relying on interfacial complexation of oppositely charged Na‐alginate (NaA) and chitosan (CS). The produced hybrid capsules exhibit high uniformity, and are biocompatible, stable, and permeable. The established system enables capsule production, 3D culture, and self‐organizing formation of human islet organoids in a continuous process by encapsulating pancreatic endocrine cells from hiPSCs. The generated islet organoids contain islet‐specific α‐ and β‐like cells with high expression of pancreatic hormone specific genes and proteins. Moreover, they exhibit sensitive glucose‐stimulated insulin secretion function, demonstrating the capability of these binary capsules to engineer human organoids from hiPSCs. The proposed system is scalable, easy‐to‐operate, and stable, which can offer a robust platform for advancing human organoids research and translational applications.
Agronomic and economic response of bread wheat to foliar zinc application
Authors: Afshar Reza Keshavarz , Chen Chengci , Zhou Shuang , Etemadi Fatemeh , He Huaqin , Li Zhaowei
Published: April 2020

Zinc (Zn) deficiency is a common micronutrient deficiency in human population, especially in regions where grain cereals are the primary supply of daily calorie intake. Zinc also performs an important role in plant growth and Zn deficiency can limit crop yield and quality. A 3‐yr field study was conducted to determine response of wheat cultivars to foliar application of Zn. Zinc sulfate was sprayed on plant canopy at a rate of 1.12 kg Zn ha−1 once (at heading) or twice (at heading and flowering). One application of Zn at heading increased grain Zn concentration by a range of 5.8 to 9.5 mg kg−1 corresponding to a 17–47% increase over the unfertilized control in various years. With the application of Zn at both heading and flowering, grain Zn concentration reached 44.3 and 52.4 mg kg−1 (in Years 2 and 3), implying an increase of 35–93% compared to the untreated control. The second application of Zn at flowering was necessary to produce grains with Zn concentration above the target level of 40 mg kg−1 to have a nutritional effect. Zinc application also marginally increased grain yield. This yield increase, however, was not adequate to offset additional production costs associated with Zn fertilization. The economic analysis revealed that the net return from the first and second Zn application was −1 and +13 USD ha−1, respectively. Therefore, it is unlikely that farmers will be motivated to adopt this system unless a price incentive or government payments are provided for farmers for producing Zn‐biofortified grains.
Sexually dimorphic phrase organization in the song of the indris (Indri indri)
Authors: Zanoli Anna , De Gregorio Chiara , Valente Daria , Torti Valeria , Bonadonna Giovanna , Randrianarison Rose Marie , Giacoma Cristina , Gamba Marco
Published: April 2020

Animal acoustic communication often takes the form of complex sequences, composed of multiple distinct acoustic units, which can vary in their degree of stereotypy. Studies of sequence variation may contribute to our understanding of the structural flexibility of primates' songs, which can provide essential ecological and behavioral information about variability at the individual, population, and specific level and provide insights into the mechanisms and drivers responsible for the evolutionary change of communicative traits. Several methods have been used for investigating different levels of structural information and sequence similarity in acoustic displays. We studied intra and interindividual variation in the song structuring of a singing primate, the indri (Indri indri), which inhabits the montane rain forests of Madagascar. Indri groups emit duets and choruses in which they combine long notes, short single units, and phrases consisting of a variable number of units (from two to six) with slightly descending frequency. Males' and females' contributions to the song differ in the temporal and frequency structure of song units and repertoire size. We calculated the similarity of phrase organization across different individual contributions using the Levenshtein distance, a logic distance that expressed the minimum cost to convert a sequence into another and can measure differences between two sequences of data. We then analyzed the degree of similarity within and between individuals and found that: (a) the phrase structure of songs varied between reproductive males and females: female structuring of the song showed a higher number of phrases if compared to males; (b) male contributions to the song were overall more similar to those of other males than were female contributions to the song of other females; (c) male contributions were more stereotyped than female contributions, which showed greater individual flexibility. The picture emerging from phrase combinatorics in the indris is in agreement with previous findings of rhythmic features and song repertoire size of the indris, which also suggested that female songs are potentially less stereotyped than those of males.
Intrapopulation variation in lower limb trabecular architecture
Authors: Mulder Bram , Stock Jay T. , Saers Jaap P. P. , Inskip Sarah A. , Cessford Craig , Robb John E.
Published: April 2020

Objectives

Trabecular structure is frequently used to differentiate between highly divergent mechanical environments. Less is known regarding the response of the structural properties to more subtle behavioral differences, as the range of intrapopulation variation in trabecular architecture is rarely studied. Examining the extent to which lower limb trabecular architecture varies when inferred mobility levels and environment are consistent between groups within a relatively homogenous population may aid in the contextualization of interpopulation differences, improve detectability of sexual dimorphism in trabecular structure, and improve our understanding of trabecular bone functional adaptation.

Materials and methods

The study sample was composed of adult individuals from three high/late medieval cemeteries from Cambridge (10th–16th c.), a hospital (n= 57), a parish cemetery (n= 44) and a friary (n= 14). Trabecular architecture was quantified in the epiphyses of the femur and tibia, using high resolution computed tomography.

Results

The parish individuals had the lowest bone volume fraction and trabecular thickness in most regions. Multiple sex differences were observed, but the patterns were not consistent across volumes of interest.

Discussion

Differences between the three groups highlight the great variability of trabecular bone architecture, even within a single sedentary population. This indicates that trabecular bone may be used in interpreting subtle behavioral differences, and suggests that multiple archaeological sites need to be studied to characterize structural variation on a population level. Variation in sex and group differences across anatomical locations further demonstrates the site‐specificity in trabecular bone functional adaptation, which might explain why little consistent sexual dimorphism has been reported previously.
Highly Reversible Cuprous Mediated Cathode Chemistry for Magnesium Batteries
Authors: Cheng Xiangyang , Zhang Zhonghua , Kong Qingyu , Zhang Qinghua , Wang Tao , Dong Shanmu , Gu Lin , Wang Xiao , Ma Jun , Han Pengxian , Lin Hong‐ji , Chen Chien‐Te , Cui Guanglei
Published: April 2020

Sluggish kinetics and poor reversibility of cathode chemistry is the major challenge for magnesium batteries to achieve high volumetric capacity. Introduction of the cuprous ion (Cu+) as a charge carrier can decouple the magnesiation related energy storage from the cathode electrochemistry. Cu+ is generated from a fast equilibrium between copper selenide electrode and Mg electrolyte during standing time, rather than in the electrochemical process. A reversible chemical magnesiation/de‐magnesiation can be driven by this solid/liquid equilibrium. During a typical discharge process, Cu+ is reduced to Cu and drives the equilibrium to promote the magnesiation process. The reversible Cu to Cu+ redox promotes the recharge process. This novel Cu+ mediated cathode chemistry of Mg battery leads to a high reversible areal capacity of 12.5 mAh cm−2 with high mass loading (49.1 mg cm−2) of the electrode. 80 % capacity retention can be achieved for 200 cycles after a conditioning process.
Air‐Stable Oxyallyl Patterns and a Switchable N‐Heterocyclic Carbene
Authors: Tomás‐Mendivil Eder , Devillard Marc , Regnier Vianney , Pecaut Jacques , Martin David
Published: April 2020

Oxyallyl derivatives are typically elusive compounds. Even recently reported “stabilized” 1,3‐diaminooxyallyl species are still highly reactive and have short lifetimes at room temperature. Herein, we report the synthesis and preliminary study of mesoionic pyrimidine derivatives that feature 1,3‐bis(dimethylamino)oxyallyl patterns with an unprecedented level of stabilization. The latter are not only insensitive towards air and moisture, but they are also compatible with the formation of an ancillary stable N‐heterocyclic carbene moiety. As the oxyallyl pattern is proton‐responsive, it allows the reversible switching of the electronic properties of the carbene, as a ligand.
Membrane Proteins Have Distinct Fast Internal Motion and Residual Conformational Entropy
Authors: O'Brien Evan S. , Fuglestad Brian , Lessen Henry J. , Stetz Matthew A. , Lin Danny W. , Marques Bryan S. , Gupta Kushol , Fleming Karen G. , Wand A. Joshua
Published: April 2020

The internal motions of integral membrane proteins have largely eluded comprehensive experimental characterization. Here the fast side‐chain dynamics of the α‐helical sensory rhodopsin II and the β‐barrel outer membrane protein W have been investigated in lipid bilayers and detergent micelles by solution NMR relaxation techniques. Despite their differing topologies, both proteins have a similar distribution of methyl‐bearing side‐chain motion that is largely independent of membrane mimetic. The methyl‐bearing side chains of both proteins are, on average, more dynamic in the ps–ns timescale than any soluble protein characterized to date. Accordingly, both proteins retain an extraordinary residual conformational entropy in the folded state, which provides a counterbalance to the absence of the hydrophobic effect. Furthermore, the high conformational entropy could greatly influence the thermodynamics underlying membrane‐protein functions, including ligand binding, allostery, and signaling.
Complex Polypropionates from a South China Sea Photosynthetic Mollusk: Isolation and Biomimetic Synthesis Highlighting Novel Rearrangements
Authors: Wu Qihao , Li Song‐Wei , Xu Heng , Wang Hong , Hu Pei , Zhang Hao , Luo Cheng , Chen Kai‐Xian , Nay Bastien , Guo Yue‐Wei , Li Xu‐Wen
Published: April 2020

Placobranchus ocellatus is well known to produce diverse and complex γ‐pyrone polypropionates. In this study, the chemical investigation of P. ocellatus from the South China Sea led to the discovery and identification of ocellatusones A–D, a series of racemic non‐γ‐pyrone polyketides with novel skeletons, characterized by a bicyclo[3.2.1]octane (1, 2), a bicyclo[3.3.1]nonane (3) or a mesitylene‐substituted dimethylfuran‐3(2H)‐one core (4). Extensive spectroscopic analysis, quantum chemical computation, chemical synthesis, and/or X‐ray diffraction analysis were used to determine the structure and absolute configuration of the new compounds, including each enantiomer of racemic compounds 1–4 after chiral HPLC resolution. An array of new and diversity‐generating rearrangements is proposed to explain the biosynthesis of these unusual compounds based on careful structural analysis and comparison with six known co‐occurring γ‐pyrones (5–10). Furthermore, the successful biomimetic semisynthesis of ocellatusone A (1) confirmed the proposed rearrangement through an unprecedented acid induced cascade reaction.
Organocatalytic Enantioselective Synthesis of Atropisomeric Aryl‐p‐Quinones: Platform Molecules for Diversity‐Oriented Synthesis of Biaryldiols
Authors: Chen Ye‐Hui , Li Heng‐Hui , Zhang Xiao , Xiang Shao‐Hua , Li Shaoyu , Tan Bin
Published: April 2020

Presented here is a class of novel axially chiral aryl‐p‐quinones as platform molecules for the preparation of non‐C2symmetric biaryldiols. Two sets of aryl‐p‐quinone frameworks were synthesized with remarkable enantiocontrol by means of chiral phosphoric acid catalyzed enantioselective arylation ofp‐quinones by central‐to‐axial chirality conversion. These aryl‐p‐quinones were then used to access a wide spectrum of highly functionalized non‐C2symmetric biaryldiols with excellent retention of the enantiopurity.
Tunable Bidirectional Electroosmotic Flow for Diffusion‐Based Separations
Authors: Bacheva Vesna , Paratore Federico , Rubin Shimon , Kaigala Govind V. , Bercovici Moran
Published: April 2020

We present a new concept for on‐chip separation that leverages bidirectional flow, to tune the dispersion regime of molecules and particles. The system can be configured so that low diffusivity species experience a ballistic transport regime and are advected through the chamber, whereas high diffusivity species experience a diffusion dominated regime with zero average velocity and are retained in the chamber. We detail the means of achieving bidirectional electroosmotic flow using an array of alternating current (AC) field‐effect electrodes, experimentally demonstrate the separation of particles and antibodies from dyes, and present a theoretical analysis of the system, providing engineering guidelines for its design and operation.
Barrier properties of thermal and electrical conductive hydrophobic multigraphitic/epoxy coatings
Authors: Campo Mónica , Redondo Osiris , Prolongo Silvia G.
Published: April 2020

Epoxy composites doped with different content of graphene nanoplatelets (GNPs) and/or carbon nanotubes (CNTs) have been manufactured. Their chemical, thermal, electrical, and mechanical behaviors have been studied, evaluating also their performance as coatings of glass fiber composite substrates. It is confirmed that the graphitic nanofillers present different efficiency as nanofillers as a function of their geometry. CNTs are much higher efficient electrical nanofillers than graphene, but an important synergetic effect is determined in the electrical conductivity of hybrid GNP/CNT/epoxy composites. In contrast, the thermal conductivity scarcely depends on the geometry of graphitic nanofillers but on the graphitic nanofiller content. Adding up to 12 wt% GNP and 1 wt% CNT, the thermal conductivity of the epoxy resin can be increased more than 300%. GNP presents high efficiency to increase the barrier properties, reducing the water absorption up to 30%. The stiffness of nanocomposites proportionally increases with graphitic addition, up to 50%, regard to the modulus of the neat epoxy resin. The adherence of coatings over glass fiber composite substrates increases by nanofiller addition due to the nanomechanical anchoring. However, the water uptake induces a higher weakening on nanodoped composites due to the preferential water absorption by the interface.
Fluctuations in glucose availability prevent global proteome changes and physiological transition during prolonged chemostat cultivations of Saccharomyces cerevisiae
Authors: Wright Naia R. , Wulff Tune , Palmqvist Eva A. , Jørgensen Thomas R. , Workman Christopher T. , Sonnenschein Nikolaus , Rønnest Nanna P. , Herrgård Markus J.
Published: April 2020

Chemostat cultivation mode imposes selective pressure on the cells, which may result in slow adaptation in the physiological state over time. We applied a two‐compartment scale‐down chemostat system imposing feast–famine conditions to characterize the long‐term (100 s of hours) response of Saccharomyces cerevisiae to fluctuating glucose availability. A wild‐type strain and a recombinant strain, expressing an insulin precursor, were cultured in the scale‐down system, and analyzed at the physiological and proteomic level. Phenotypes of both strains were compared with those observed in a well‐mixed chemostat. Our results show that S. cerevisiae subjected to long‐term chemostat conditions undergoes a global reproducible shift in its cellular state and that this transition occurs faster and is larger in magnitude for the recombinant strain including a significant decrease in the expression of the insulin product. We find that the transition can be completely avoided in the presence of fluctuations in glucose availability as the strains subjected to feast–famine conditions under otherwise constant culture conditions exhibited constant levels of the measured proteome for over 250 hr. We hypothesize possible mechanisms responsible for the observed phenotypes and suggest experiments that could be used to test these mechanisms.
Stent as a bridge to surgery or immediate colectomy for malignant right colonic obstruction: propensity-scored, national database study
Authors: Sakamoto T , Fujiogi M , Lefor A K , Matsui H , Fushimi K , Yasunaga H
Published: April 2020

Background

The aim of this study was to compare perioperative outcomes of urgent colectomy and placement of a self-expanding metallic stent followed by colectomy for patients with malignant right colonic obstruction. Right-sided malignant obstruction is less common than left-sided. Stenting for malignant left colonic obstruction has been reported to reduce postoperative complications. However, the impact of stenting for malignant right colonic obstruction remains undefined.

Methods

The study included patients with right-sided malignant obstruction or stenosis undergoing colectomy between April 2012 and March 2017 identified from a nationwide database. Propensity score matching analysis was used to compare mortality and morbidity rates, proportion receiving a stoma and postoperative stay between urgent colectomy and stent groups.

Results

From 9572 patients, 1500 pairs were generated by propensity score matching. There was no significant difference in in-hospital mortality between the urgent colostomy and stent groups (1·6 versus 0·9 per cent respectively; P = 0·069). Complications were more common after urgent colectomy than stenting (22·1 versus 19·1 per cent; P = 0·042). Surgical-site infection was more likely with urgent colectomy (7·1 versus 4·4 per cent; P = 0·001). There was no significant difference between the two groups in anastomotic leakage (3·8 versus 2·6 per cent; P = 0·062). The proportion of patients needing a stoma was higher with urgent colectomy than primary treatment with stents (5·1 versus 1·7 per cent; P < 0·001). Postoperative stay was longer after urgent colectomy (15 versus 13 days; P < 0·001).

Conclusion

Stenting followed by colectomy in patients with malignant right colonic obstruction may provide more favourable perioperative outcomes than urgent colectomy.