Intercellular Coupling of the Cell Cycle and Circadian Clock in Adult Stem Cell Culture.

Circadian clock-gated cell division cycles are observed from cyanobacteria to mammals via intracellular molecular connections between these two oscillators. Here we demonstrate WNT-mediated intercellular coupling between the cell cycle and circadian clock in 3D murine intestinal organoids (enteroids). The circadian clock gates a population of cells with heterogeneous cell-cycle times that emerge as 12-hr synchronized cell division cycles. Remarkably, we observe reduced-amplitude oscillations of circadian rhythms in intestinal stem cells and progenitor cells, indicating an intercellular signal arising from differentiated cells governing circadian clock-dependent synchronized cell division cycles. Stochastic simulations and experimental validations reveal Paneth cell-secreted WNT as the key intercellular coupling component linking the circadian clock and cell cycle in enteroids.

Protocol and validity testing of femoroacetabular posterior translation with dynamic hip ultrasonography.

OBJECTIVE: To describe femoroacetabular posterior translation (FAPT) using dynamic hip ultrasonography (DHUS), and to determine the inter- and intra-rater reliability of hip ultrasound measurements of FAPT. MATERIALS AND METHODS: The study design was a feasibility study of 13 healthy young adults (26 hips) using test-retest analysis. The data was collected prospectively over a 2-week time period. Three DHUS measurements (posterior neutral (PN), flexion, adduction, and internal rotation (PFADIR), and stand and load (PStand) were measured by four independent raters (2 senior who divided the cohort, 1 intermediate, 1 junior) at two time points for bilateral hips of each participant. Reliability was assessed by calculating the intraclass correlation coefficient (ICC) along with 95% confidence intervals (CIs) for each rater and across all raters. RESULTS: A total of 468 US scans were completed. The mean age of the cohort was 25.7 years (SD 5.1 years) and 54% were female. The inter-rater reliability was excellent for PFADIR (ICC 0.85 95% CI 0.76-0.91), good for PN (ICC 0.69 95% CI 0.5-0.81), and good for PStand (ICC 0.72 95% CI 0.55-0.83). The intra-rater reliability for all raters was good for PFADIR (ICC 0.60 95% CI 0.44-0.73), fair for PN (ICC 0.42 95% CI 0.21-0.59), and fair for PStand (ICC 0.42 95% CI 0.22-0.59). CONCLUSION: This is the first study to present a protocol using dynamic ultrasonography to measure FAPT. DHUS measure for FAPT was shown to be reliable across raters with varying levels of ultrasound experience.

Whole-Genome Sequencing to Predict Antimicrobial Susceptibility Profiles in Neisseria gonorrhoeae.

BACKGROUND: Neisseria gonorrhoeae is a major public health problem due to increasing incidence and antimicrobial resistance. Genetic markers of reduced susceptibility have been identified; the extent to which those are representative of global antimicrobial resistance is unknown. We evaluated the performance of whole-genome sequencing (WGS) used to predict susceptibility to ciprofloxacin and other antimicrobials using a global collection of N. gonorrhoeae isolates. METHODS: Susceptibility testing of common antimicrobials and the recently developed zolifodacin was performed using agar dilution to determine minimum inhibitory concentrations (MICs). We identified resistance alleles at loci known to contribute to antimicrobial resistance in N. gonorrhoeae from WGS data. We tested the ability of each locus to predict antimicrobial susceptibility. RESULTS: A total of 481 N. gonorrhoeae isolates, collected between 2004 and 2019 and making up 457 unique genomes, were sourced from 5 countries. All isolates with demonstrated susceptibility to ciprofloxacin (MIC ≤0.06 µg/mL) had a wild-type gyrA codon 91. Multilocus approaches were needed to predict susceptibility to other antimicrobials. All isolates were susceptible to zoliflodacin, defined by an MIC ≤0.25 µg/mL. CONCLUSIONS: Single marker prediction can be used to inform ciprofloxacin treatment of N. gonorrhoeae infection. A combination of molecular markers may be needed to determine susceptibility for other antimicrobials.

Impact of Carbon Source Supplementations on Pseudomonas aeruginosa Physiology.

Pseudomonas aeruginosa is an opportunistic pathogen highly resistant to a wide range of antimicrobial agents, making its infections very difficult to treat. Since microorganisms need to perpetually adapt to their surrounding environment, understanding the effect of carbon sources on P. aeruginosa physiology is therefore essential to avoid increasing drug-resistance and better fight this pathogen. By a global proteomic approach and phenotypic assays, we investigated the impact of various carbon source supplementations (glucose, glutamate, succinate, and citrate) on the physiology of the P. aeruginosa PA14 strain. A total of 581 proteins were identified as differentially expressed in the 4 conditions. Most of them were more abundant in citrate supplementation and were involved in virulence, motility, biofilm development, and antibiotic resistance. Phenotypic assays were performed to check these hypotheses. By coupling all this data, we highlight the importance of the environment in which the bacterium evolves on its metabolism, and thus the necessity to better understand the metabolic pathways implied in its adaptative response according to the nutrient availability.

Nutrient status regulates MED19a phase separation for ORESARA1-dependent senescence.

The mediator complex is highly conserved in eukgaryotes and is integral for transcriptional responses. Mediator subunits associate with signal-responsive transcription factors (TF) to activate expression of specific signal-responsive genes. As the key TF of Arabidopsis thaliana senescence, ORESARA1 (ORE1) is required for nitrogen deficiency (-N) induced senescence; however, the mediator subunit that associates with ORE1 remains unknown. Here, we show that Arabidopsis MED19a associates with ORE1 to activate -N senescence-responsive genes. Disordered MED19a forms inducible nuclear condensates under -N that is regulated by decreasing MED19a lysine acetylation. MED19a carboxyl terminus (cMED19a) harbors a mixed-charged intrinsically disordered region (MC-IDR) required for ORE1 interaction and liquid-liquid phase separation (LLPS). Plant and human cMED19 are sufficient to form heterotypic condensates with ORE1. Human cMED19 MC-IDR, but not yeast cMED19 IDR, partially complements med19a suggesting functional conservation in evolutionarily distant eukaryotes. Phylogenetic analysis of eukaryotic cMED19 revealed that the MC-IDR could arise through convergent evolution. Our result of MED19 MC-IDR suggests that plant MED19 is regulated by phase separation during stress responses.

A prospective cohort study on the association between waterpipe tobacco smoking and gastric cancer mortality in Northern Vietnam.

Tobacco consumption, as a worldwide problem, is a risk factor for several types of cancer. In Vietnam, tobacco consumption in the form of waterpipe tobacco smoking is common. This prospective cohort study aimed to study the association between waterpipe tobacco smoking and gastric cancer mortality in Northern Vietnam. A total of 25,619 eligible participants were followed up between 2008 and 2019. Waterpipe tobacco and cigarette smoking data were collected; semi-quantitative food frequency and lifestyle questionnaires were also utilized. Gastric cancer mortality was determined via medical records available at the state health facilities. A Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). During 314,992.8 person-years of follow-up, 55 men and 25 women deaths due to gastric cancer were identified. With never-smokers as the reference, the risk of gastric cancer mortality was significantly increased in participants who were ever-smoking (HR = 2.43, 95% CI = 1.35-4.36). The positive risk was also observed in men but was not significantly increased in women. By types of tobacco use, exclusive waterpipe smokers showed a significantly increased risk of gastric cancer mortality (HR = 3.22, 95% CI = 1.67-6.21) but that was not significantly increased in exclusive cigarette smokers (HR = 1.90, 95% CI = 0.88-4.07). There was a significant positive association between tobacco smoking and gastric cancer death for indicators of longer smoking duration, higher frequency per day, and cumulative frequency of both waterpipe and cigarette smoking. Waterpipe tobacco smoking would significantly increase the risk of gastric cancer mortality in the Vietnamese population. Further studies are required to understand the waterpipe tobacco smoking-driven gastric cancer burden and promote necessary interventions.

Does Complexity Always Correlate With Compensation? An Analysis of Work Relative Value Units in 3 Common Nerve Decompression Syndromes.

BACKGROUND: Work relative value units (wRVUs) are part of Resource Based Relative Value Scale system. It is expected that a more difficult and time-consuming procedure would yield higher wRVUs. Brachial plexus nerve decompression surgery is a more time-consuming procedure compared with carpal and cubital tunnel procedures. The aim of this study was to analyze physician reimbursement in upper limb decompression procedures by comparing mean operative times, wRVUs per minute, and dollars per minute. METHODS: A retrospective cohort study was conducted from June 2016 to June 2019, including all patients who underwent carpal tunnel, cubital tunnel, and brachial plexus release procedures. Operating time was collected, and calculations of mean operative time, wRVUs per minute, and dollars per minute were performed and compared between groups. RESULTS: A total of 209 cases were included. Carpal tunnel accounted for 75.1% of the cases, followed by cubital tunnel and brachial plexus releases. Brachial plexus release had the highest median operative time (147 minutes), followed by cubital tunnel (57 minutes) and carpal tunnel release (16 minutes, P < 0.0001). Carpal tunnel release procedures had a significantly higher wRVUs per minute (0.310) when compared with cubital tunnel and brachial pleaxus release procedures, 0.127 and 0.077, respectively (P < 0.0001). Same was true for dollars per minute; carpal tunnel procedures yielded significantly more compensation than cubital tunnel and thoracic outlet procedures (P < 0.0001). CONCLUSIONS: More complex and time-consuming procedures yielded a lower reimbursement for physicians. The current work relative unit system does not account adequately for the time spent in each procedure.

Dissociation of hydrogen peroxide in water and methanol through a biased molecular dynamics investigation.

The two dissociation channels of HOOH, namely, HOOH and HOOH, in water and methanol are investigated using umbrella-sampling ab initio molecular dynamics. Our potential of mean force calculations reveals the HOOH dissociation to be more favorable in methanol with a free energy barrier of 7.56 kcal/mol, while the HOOH dissociation possesses a free energy barrier of 11.46 kcal/mol. In water, the HOOH dissociation channel is more favorable (8.25 kcal/mol), while the HOOH dissociation process requires a higher free energy (11.28 kcal/mol). Such reaction favorability can be explained by inspecting the formation of secondary radical species during the course of multiple hydrogen donating-accepting processes in each reaction channel. The radical species, that is, H3 O• (observed in water) and CH3 OH2• (observed in methanol), are the first subordinate species upon the HOOH dissociation. For the HOOH dissociation channel in methanol, the secondary species such as water and formaldehyde can be observed, while the re-generation of HOOH in water can be spotted.

Antibody-Conjugated Nanocarriers for Targeted Antibiotic Delivery: Application in the Treatment of Bacterial Biofilms.

Conventional antibiotic treatment is in most cases insufficient to eradicate biofilm-related infections, resulting in high risk of treatment failure and recurrent infections. Recent studies have shown that novel methods of antibiotic delivery can improve clinical outcomes and reduce the emergence of antibiotic resistance. The objectives of this work were to develop and evaluate a targeting nanocarrier system that enables effective delivery of antimicrobial drugs to Staphylococcus aureus, a commonly virulent human pathogen. For this purpose, we first prepared a formulation of polymeric nanoparticles (NPs) suitable for encapsulation and sustained release of antibiotics. A specific antibody against S. aureus was used as a targeting ligand and was covalently immobilized onto the surface of nanoparticulate materials. It was demonstrated that the targeting NPs preferentially bound S. aureus cells and presented an elevated accumulation in the S. aureus biofilm. Compared to free-form antibiotic, the antibiotic-loaded targeting NPs significantly enhanced in vitro bactericidal activity against S. aureus both in planktonic and biofilm forms. Using a mouse infection model, we observed improved therapeutic efficacy of these antibiotic-loaded NPs after a single intravenous administration. Taken together, our studies show that the targeting nanoparticulate system could be a promising strategy to enhance the biodistribution of antibiotics and thereby improve their efficacy.

Student Behavior Recognition System for the Classroom Environment Based on Skeleton Pose Estimation and Person Detection.

Human action recognition has attracted considerable research attention in the field of computer vision, especially for classroom environments. However, most relevant studies have focused on one specific behavior of students. Therefore, this paper proposes a student behavior recognition system based on skeleton pose estimation and person detection. First, consecutive frames captured with a classroom camera were used as the input images of the proposed system. Then, skeleton data were collected using the OpenPose framework. An error correction scheme was proposed based on the pose estimation and person detection techniques to decrease incorrect connections in the skeleton data. The preprocessed skeleton data were subsequently used to eliminate several joints that had a weak effect on behavior classification. Second, feature extraction was performed to generate feature vectors that represent human postures. The adopted features included normalized joint locations, joint distances, and bone angles. Finally, behavior classification was conducted to recognize student behaviors. A deep neural network was constructed to classify actions, and the proposed system was able to identify the number of students in a classroom. Moreover, a system prototype was implemented to verify the feasibility of the proposed system. The experimental results indicated that the proposed scheme outperformed the skeleton-based scheme in complex situations. The proposed system had a 15.15% higher average precision and 12.15% higher average recall than the skeleton-based scheme did.

Ambient air monitoring around the dioxin remediation site in Da Nang, Vietnam, using passive air samplers.

The concentrations and temporal variations of polychlorodibenzo-p-dioxins and polychlorodibenzofurans (PCDDs/PCDFs) in ambient air between March 2013 and February 2017 were investigated by passive air samplers containing polyurethane foam (PUF) disks in the dioxin remediation area using in-pile thermal desorption (IPTD) technology at Da Nang airport, Vietnam. The PCDD/PCDF concentrations in ambient air at each site depended on the location of the emission sources and the wind direction, the dioxin contamination level of excavated materials, the periods of excavation and transport, and the operation of the IPTD treatment system. The PCDD/PCDF concentrations were the highest in the former Agent Orange mixing and loading area (AOMLA), which was the closest to the IPTD system, with total toxic equivalent (TEQ) values ranging from 0.437 to 15.3 pg/PUF/day. The total TEQ concentrations in the Sen Lake area ranged from 0.138 to 2.41 pg/PUF/day. The lowest concentration of PCDDs/PCDFs occurred in the northern perimeter area, with total TEQ values ranging from 0.164 to 0.972 pg/PUF/day. The decreasing trend of the PCDD/PCDF concentrations in ambient air was confirmed over time at all three monitoring sites, among which there was a strong decrease in the former AOMLA after February 2015. Residents living near the Da Nang airport were at a low risk of being exposed to PCDDs/PCDFs through inhalation during remediation project implementation, while residents living close to the former AOMLA faced elevated risks with an average daily dose of PCDDs/PCDFs through inhalation ranging from 0.017 to 0.82 pg TEQ/kg body weight/day.

Femoral Injury Over the Site of Spontaneous Regression of an Osteochondroma in a Teenage Athlete.

ABSTRACT: The spontaneous regression of an osteochondroma is extremely rare. We report a case of medial femoral condyle impaction fracture over the site of spontaneous regression of a pedunculated osteochondroma discovered on advanced imaging after an acute injury in a 16-year-old male American football athlete. Although spontaneous regression of an osteochondroma has been described, the case presented reveals questions regarding resultant architectural changes to the bone after resorption, leaving it prone to injury. This is the first case that describes increased injury risk potential at the site of osteochondral regression.

Point-of-Care Ultrasound, the New Musculoskeletal Physical Examination.

ABSTRACT: The availability of handheld ultrasound offers physicians an opportunity to better define anatomy and pathophysiology, thus enhancing the diagnostic capabilities of a standard physical examination. The medical community increasingly embraces the potential for point-of-care ultrasound across medical specialties. The primary aim of this review was to identify and compile information on the current clinical utility of point-of-care ultrasound for musculoskeletal examination. This information will enable health care providers to understand the current utility and potential of musculoskeletal point-of-care ultrasound, thus facilitating its appropriate adoption into clinical practice.

Clinical features, isolation, and complete genome sequence of severe acute respiratory syndrome coronavirus 2 from the first two patients in Vietnam.

In January 2020, we identified two severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients in a familial cluster with one person coming from Wuhan, China. The complete genome sequences of two SARS-CoV-2 strains isolated from these patients were identical and 99.98% similar to strains isolated in Wuhan. This is genetically suggestive of human-to-human transmission of SARS-CoV-2 and indicates Wuhan as the most plausible origin of the early outbreak in Vietnam. The younger patient had a mild upper respiratory illness and a brief viral shedding, whereas the elderly with multi-morbidity had pneumonia, prolonged viral shedding, and residual lung damage. The evidence of nonsynonymous substitutions in the ORF1ab region of the viral sequence warrants further studies.

Trends in antimicrobial resistance in Neisseria gonorrhoeae in Hanoi, Vietnam, 2017-2019.

BACKGROUND: Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is an emerging global health threat. Surveillance of AMR in N. gonorrhoeae in the Western Pacific Region is important, as resistant strains have typically emerged from this region. There are sparse data regarding antibiotic susceptibility of N. gonorrhoeae from Vietnam. This study aimed to provide updated data on antibiotic susceptibilities in N. gonorrhoeae isolates from Hanoi, Vietnam. METHODS: From 2017 to 2019, 409 N. gonorrhoeae clinical isolates were collected at the National Hospital for Venereology and Dermatology in Hanoi, Vietnam. Antibiotic susceptibility testing was performed by disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) protocol. The zone diameters of inhibition were recorded and interpreted according to standard CLSI criteria, except for azithromycin, due to the absence of CLSI interpretation. Categorical variables were analyzed by Chi-square and Fisher's exact tests. Linear regression was used to evaluate zones of inhibition by year. RESULTS: Among the 409 isolates, no isolates were susceptible to penicillin, 98.3% were resistant to ciprofloxacin, and all isolates were susceptible to spectinomycin. There were 122/407 (30.0%) isolates resistant to azithromycin and there was an association between resistance and year (p <  0.01), ranging from 15.3% of isolates in 2017 to 46.7% of the isolates in 2018. Resistance to cefixime was found in 13/406 (3.2%) of isolates and there was no association by year (p = 0.30). Resistance to ceftriaxone occurred in 3/408 (0.7%) of isolates. Linear regression indicated the zone of inhibition diameters decreased by 0.83 mm each year for ceftriaxone (95% CI: - 1.3, - 0.4; p <  0.01) and decreased by 0.83 mm each year (95% CI: - 1.33, - 0.33; p <  0.01) for azithromycin; the association was not significant for cefixime (p = 0.07). CONCLUSIONS: We found decreasing susceptibility of N. gonorrhoeae to ceftriaxone and azithromycin, as well as a high prevalence of resistance to azithromycin, among isolates in Hanoi, Vietnam from 2017 to 2019. The trends of decreasing susceptibility to first-line treatments are concerning and highlight the urgency of addressing antimicrobial resistance in N. gonorrhoeae. Expanded surveillance efforts within the Western Pacific Region are critical to monitoring trends and informing treatment guidelines.

Reaction probability and kinetics of water splitting on the penta-NiAs2 monolayer from an ab initio molecular dynamics investigation.

The reaction probability and kinetics of the water splitting process on the penta-NiAs2 monolayer are studied using ab initio molecular dynamics simulations. A total of 100 trajectories are investigated, in which a H2O molecule is set to strike the surface with a translational energy of 1 eV or 2 eV. The results show that the NiAs2 monolayer is an excellent candidate for the activation of water splitting with a reaction probability of 94% for both energy levels. Interestingly, the kinetics of two O-H dissociation stages varies greatly with respect to the inletting translational energy. Interpreting the reaction data for the 1 eV case, we conclude that O-H1 and O-H2 dissociations are first-order processes. However, such dissociation steps become pseudo-zeroth order in the 2 eV case. At the time of the dissociation, the force acting on atoms and the principal component analysis suggest that the two OH breaking stages behave like harmonic springs until reaching the dissociation.

Plasmodium vivax morbidity after radical cure: A cohort study in Central Vietnam.

BACKGROUND: In Vietnam, the importance of vivax malaria relative to falciparum during the past decade has steadily increased to 50%. This, together with the spread of multidrug-resistant Plasmodium falciparum, is a major challenge for malaria elimination. A 2-year prospective cohort study to assess P. vivax morbidity after radical cure treatment and related risk factors was conducted in Central Vietnam. METHODS AND FINDINGS: The study was implemented between April 2009 and December 2011 in four neighboring villages in a remote forested area of Quang Nam province. P. vivax-infected patients were treated radically with chloroquine (CQ; 25 mg/kg over 3 days) and primaquine (PQ; 0.5 mg/kg/day for 10 days) and visited monthly (malaria symptoms and blood sampling) for up to 2 years. Time to first vivax recurrence was estimated by Kaplan-Meier survival analysis, and risk factors for first and recurrent infections were identified by Cox regression models. Among the 260 P. vivax patients (61% males [159/260]; age range 3-60) recruited, 240 completed the 10-day treatment, 223 entered the second month of follow-up, and 219 were followed for at least 12 months. Most individuals (76.78%, 171/223) had recurrent vivax infections identified by molecular methods (polymerase chain reaction [PCR]); in about half of them (55.61%, 124/223), infection was detected by microscopy, and 84 individuals (37.67%) had symptomatic recurrences. Median time to first recurrence by PCR was 118 days (IQR 59-208). The estimated probability of remaining free of recurrence by month 24 was 20.40% (95% CI [14.42; 27.13]) by PCR, 42.52% (95% CI [35.41; 49.44]) by microscopy, and 60.69% (95% CI [53.51; 67.11]) for symptomatic recurrences. The main risk factor for recurrence (first or recurrent) was prior P. falciparum infection. The main limitations of this study are the age of the results and the absence of a comparator arm, which does not allow estimating the proportion of vivax relapses among recurrent infections. CONCLUSION: A substantial number of P. vivax recurrences, mainly submicroscopic (SM) and asymptomatic, were observed after high-dose PQ treatment (5.0 mg/kg). Prior P. falciparum infection was an important risk factor for all types of vivax recurrences. Malaria elimination efforts need to address this largely undetected P. vivax transmission by simultaneously tackling the reservoir of P. falciparum and P. vivax infections.

Low concordance of oral and genital HPV infection among male patients with sexually transmitted infections in Vietnam.

BACKGROUND: Human papillomavirus (HPV) causes cancers in men, including penile, anal, and oropharyngeal cancers. This cross-sectional study aimed to investigate the prevalence, the genotypes, and the risk factors of HPV infections in the oral cavity, compared to those in the genitals, among males diagnosed with sexually transmitted infections (STIs) in Vietnam. METHODS: Oral, urinary, penile, and urethral samples were collected from 198 male Vietnamese patients with STIs (median age 31.0 years, range 17-68). HPV DNA was isolated and amplified with PCR, with modified and/or original GP5+/GP6+ primers. Samples were genotyped with a gene array assay and/or population sequencing. RESULTS: HPV DNA was detected in 69 (34.8%) of 198 patients. Of these, 16 patients (8.1%) had infections in the oral cavity and 58 (29.3%) had infections in the genitals (4.5% in the urine, 25.8% in the penis, and 8.1% in the urethra). The concordance of HPV infections between the oral cavity and the genitals was poor (kappa = 0.01). Of the 16 patients with oral HPV DNA, 11 (68.8%) had no HPV DNA in the genitals. In the remaining five patients, HPV DNA was found at both sites, but only one showed similar strains at both sites. In the other four patients, the HPV genotypes were completely discordant between these sites. HPV18 was the most common high-risk HPV genotype in both oral (9/16, 56.3%) and genital (10/58, 17.2%) sites. Multivariable analyses showed that older age (OR 1.05), higher education (OR 2.17), and no knowledge of STIs (OR 4.21) were independent risk factors for genital HPV infections; in contrast, only older age (OR 1.05) was an independent risk factor for oral HPV infections. CONCLUSIONS: The low concordance of HPV genotypes between oral and genital infection sites suggested that the acquisition, persistence, and/or clearance of HPV infections were different between these sites. Although HPV DNA was detected significantly less frequently in oral samples than in genital samples, oral samples should also be used for HPV screening in men.

A proton transfer mechanism along the PO4 anion chain in the [Zn(HPO4)(H2PO4)]2- coordination polymer.

In this study, we revisit the proton transfer mechanism in [Zn(HPO4)(H2PO4)]2-, a coordination polymer possessing high proton conductivity. In a previous report [N. Phattharasupakun, J. Wutthiprom, S. Kaenket, Th. Maihom, J. Limtrakul, M. Probst, S. S. Nagarkar, S. Horike and M. Sawangphruk, Chem. Commun., 2017, 53, 11786-11789], it was hypothesized that protons could move along the ImH+ chain involving phosphate anions within the polymer structure, with energy barriers >1.3 eV. Adopting M06-2X calculations to examine the reaction pathway, we observe that it is much more favorable for H+ to move along a one-dimensional channel formed by HPO42- and H2PO4- anions. Within a unit cell, the proton hopping process can be divided into three elementary steps. For the forward proton transfer direction, the maximum energy barrier is only 0.04 eV, while that of the backward direction is 0.27 eV. Even though the barriers of the backward direction seem to outreach the barriers of the forward direction, both are still low in comparison with those reported in the literature. Moreover, we also point out the involvement of PO4 rotation during the proton transfer process. Activation energies of 0.37 eV and 0.15 eV are required for single steps of rotation of the phosphate anion. Both H+ translation (hopping) and rotation steps of PO4 anions simultaneously participate in the course of proton transfer in the coordination polymer.

Enhancement of dairy sheep cheese eating quality with increased n-3 long-chain polyunsaturated fatty acids.

This study investigated the effect of different plant oil-infused and rumen-protected wheat-based pellets containing eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) on n-3 long-chain (≥C20) polyunsaturated fatty acid (LC-PUFA) content, fatty acid recovery, and sensory attributes of ripened cheese from dairy sheep. During a 10-wk supplementary feeding trial, 60 dairy ewes balanced by live weight, milk yield, parity, and sire breed were randomly divided into 6 groups that were (1) supplemented with on-farm existing commercial wheat-based pellets without oil inclusion (control) or supplemented with wheat-based pellets infused with 50 mL/kg dry matter of oils from (2) canola, (3) rice bran, (4) flaxseed, (5) safflower, and (6) rumen-protected EPA + DHA. Milk samples from each treatment were collected separately by sire breed during the experimental period for cheese processing at the end of the experiment. Twelve batches of cheese (2 batches per treatment) were processed and ripened for 120 d. Three cheese samples were collected and analyzed for each cheese making session (total of 36 cheese samples) at d 120 of ripening. Processed cheese of rumen-protected EPA + DHA had the most efficiency at elevating total n-3 LC-PUFA [total EPA + DHA + docosapentaenoic acid (DPA, 22:5n-3] content compared with the control (0.49 vs. 0.28%). Flaxseed elicited the greatest enhancement of α-linolenic acid (ALA, 18:3n-3), whereas safflower was the most effective diet in enhancing the level of linoleic acid (18:2n-6) in cheese (1.29 vs. 0.71% and 4.8 vs. 3.3%, respectively). Parallel recoveries of n-3 and n-6 LC-PUFA were observed across all treatments except for α-linolenic acid and EPA. Cheese eating sensory traits were also highly affected by oil supplementation, with the highest score of 7.5 in cheese from the rice bran and flaxseed treatments. These results provide new insights into the biological mechanisms and processes that determine dairy ewe milk productivity by underpinning the vital biological role of n-3 LC-PUFA in not only enhancing the healthy composition of cheese from ewes but also translating it into consumer acceptability.