Phylogenetic identification of lactic acid bacteria isolates and their effects on the fermentation quality of sweet sorghum (Sorghum bicolor) silage

AIM

To isolate, screen and identify the lactic acid bacteria (LAB) from elephant silage during the process of the fermentation and their effects on the fermentation quality of sweet sorghum silage.

METHODS AND RESULTS

The isolated strains were identified based on morphological, physiological and biochemical characteristics as well as 16S rRNA analysis. Seven LAB strains were isolated from elephant grass silage. Three strains (Pediococcus acidilactici (AZZ1), Lactobacillus plantarum subsp. plantarum (AZZ4), L. plantarum subsp. argentoratensis (AZZ7) and one commercial bacteria L. plantarum, ecosyl MTD/1(CB)) were chosen as additives at 6 log colony forming units per gram of fresh sweet sorghum grass in laboratory silos (680 g). Silos for each treatment were opened after 5, 7, 14, 30 and 60 days, respectively. All isolates were characterized as Gram-positive, catalase-negative and grow normally in 6·5% NaCl. The strains AZZ1, AZZ2 and AZZ5, were identified as Pediococcus genus while AZZ3, AZZ4, AZZ6 and AZZ7 were Lactobacillus genus. Compared to the control, all the isolates improved the silage quality of sweet sorghum silage, indicated by significantly (P < 0·05) lower pH and ammonia-nitrogen contents and undesirable micro-organism counts, and higher lactic acid (LA) contents and ratios of lactic acid/acetic acid. During ensiling, AZZ4 performed better among all of inoculants, indicated by significantly (P < 0·05) decreased on pH and ammonia-N contents and higher increased on LA contents.

CONCLUSION

Strain AZZ4 is recommended as starter culture for sweet sorghum.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first time to investigate the effects of LAB isolates from elephant grass silage and use them as additives, which is to find out how LAB inoculants improve the fermentation quality of sweet sorghum silage.

Serum Stem Cell Factor Level Predicts Decline in Kidney Function in Healthy Aging Adults

BACKGROUND AND OBJECTIVES

Stem cell factor (SCF), the ligand of the c-kit receptor, actively participates in the organ reconstruction and fibrosis associated with various diseases, including kidney disease. However, it remains unclear whether SCF plays a role in kidney aging.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

In the present study, we measured the serum SCF level, estimated glomerular filtration rate (eGFR), and other biological parameters in a Chinese Han group of 892 subjects, and explored the relationship between SCF level and renal function during aging; we sought to define novel biomarkers of kidney aging.

RESULTS

Multiple linear regression was used to select potential indicators of decline in renal function. Only age, SCF level, and 25% maximum expiratory flow (25% MEF) were significant predictors after redundancy analysis (|r| > 0.70 and P < 0.05). Multiple linear regression showed that the relationship among eGFR, SCF level, and age could be described as follows: eGFR = 154.486 - (0.846 × age) - (0.011 × SCF level).

CONCLUSIONS

We found no between-gender difference in the effect of SCF on kidney aging. In conclusion, the SCF level is an ideal biomarker of renal aging and may help to predict changes in eGFR during aging.

The fungal-resistance factors BmSPI38 and BmSPI39 predominantly exist as tetramers, not monomers, in Bombyx mori

Previous studies have indicated that trypsin inhibitor-like cysteine-rich domain (TIL)-type protease inhibitors, BmSPI38 and BmSPI39, suppress conidial germination and integument penetration of entomopathogenic fungi by inhibiting their cuticle-degrading proteases and might functions as fungal-resistance factors in the silkworm. To date, the physiological forms and functional significance of multimerization of BmSPI38 and BmSPI39 remain unknown. In this study, we investigated the physiological forms of BmSPI38 and BmSPI39 in Bombyx mori silkworms using multiple complementary methods, including activity staining, reducing and nonreducing sodium dodecyl sulfate polyacrylamide gel electrophoresis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, western blotting and immunofluorescence. We found that recombinant BmSPI38 and BmSPI39 tend to form homologous multimers, and their dimers, trimers and tetramers possessed intense inhibitory activity against subtilisin A from Bacillus licheniformis. In contrast, their monomers showed no detectable inhibitory activity. Both BmSPI38 and BmSPI39 also exist mainly as stable tetramers in silkworm tissues, and they also predominantly function as a tetramer in these tissues. This study is the first to demonstrate this preferred quaternary form of a TIL-type protease inhibitor and will likely help to elucidate the mechanisms of BmSPI38 and BmSPI39 in the innate immune response of the silkworm.

Effects of storage temperature and combined microbial inoculants on fermentation end products and microbial populations of Italian ryegrass (Lolium multiflorum Lam.) silage

AIMS

To examine five lactic acid bacteria (LAB) strains (LCG9, LTG7, I5, TG1 and LI3) isolated from the Tibetan Plateau, and evaluate their combined effects on the silage quality of Italian ryegrass (Lolium multiflorum Lam.) at three temperatures (10, 15 and 25°C).

METHODS AND RESULTS

The isolated strains were evaluated by morphological, physiological and biochemical tests. Six combined inoculants LCG9+LI3, LCG9+I5, LCG9+TG1, LTG7+LI3, LTG7+I5 and LTG7+TG1 were added to Italian ryegrass for ensiling 30 days in laboratory silos (1L) at various temperatures, respectively. All the isolates could grow normally at 5-20°C, pH 3·5-7·0 and NaCl (3·0, 6·5%). Compared to three corresponding controls, all the inoculants improved the silage quality of Italian ryegrass at different temperatures, indicated by markedly (P < 0·05) higher lactic acid (LA) contents and ratios of lactic acid/acetic acid (LA/AA), and lower pH and ammonia nitrogen (NH3 -N) contents and undesirable micro-organism counts. At 10°C, LTG7+LI3, I5 or TG1 inoculants performed superior to LCG9+LI3, I5 or TG1 inoculants, evidenced by distinctly (P < 0·05) higher LA contents and ratios of LA/AA, and lower pH and NH3 -N contents. LTG7+LI3 or TG1 silages had obviously (P < 0·05) higher LAB counts than LTG7+I5 silage at 10°C.

CONCLUSIONS

Therefore, the combined inoculants LTG7 + LI3 or TG1 are recommended as starter cultures for Italian ryegrass silage at low temperatures.

SIGNIFICANCE AND IMPACT OF THE STUDY

Temperature is a key factor affecting ensilage. In cold regions, low temperature could be an adverse environmental condition during ensiling. However, few studies have focused on improving silage quality at low temperatures. Moreover, analysis of effects of combined LAB strains with their physiological and biochemical characteristics help us use combined LAB inoculants to realize the fermentation optimization.

Obesity, weight change, and mortality in older adults with metabolic abnormalities

BACKGROUND AND AIMS

It is expected that older adults with metabolic abnormalities may benefit from weight loss; however, data on this population are limited. Our study was to assess the effect of obesity and weight change on mortality risk in older adults with metabolic abnormalities.

METHODS AND RESULTS

A total of 3649 Chinese older adults aged 60-90 years with metabolic abnormalities were included between 2000 and 2014. Weight change between two health checkup periods was calculated. During a median follow-up period of 37 months, 503 all-cause mortality and 235 cardiovascular disease mortality occurred. Death rate was the lowest in overweight participants and in the participants with weight stability. After adjustment for covariates, hazard ratios (95% confidence intervals) of overweight participants for all-cause mortality and cardiovascular mortality were 0.71 (0.59, 0.86) and 0.72 (0.55, 0.95), respectively, whereas obesity was not significantly associated with mortality risk. Furthermore, relative to weight stability, risks of mortality significantly increased with the increase in weight loss or weight gain, except small weight gain. These associations were unchanged when the participants were stratified by baseline covariates and even when several definitions of weight change were considered.

CONCLUSIONS

Overweight was associated with less mortality risk, and obesity was not associated with mortality risk in older adults with metabolic abnormalities. Mortality risk increased with the increase in weight loss or weight gain, regardless of body weight levels at the baseline. These findings suggest that maintaining a stable weight may be the best choice in older adults with metabolic abnormalities.

Zr-Induced high temperature resistance of polymer microsphere based on double crosslinked structure

In order to obtain polymer microspheres for profile control and water shutoff with high temperature resistance and good swelling properties, micrometer microspheres with a double crosslinked structure were synthesized using the monomers acrylamide (AM), N-vinylpyrrolidone (NVP) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS), an initiator of potassium persulfate, a crosslinking agent of N,N-methylene bis acrylamide and zirconium acetate. The crosslinked Zr–AM/NVP/AMPS microspheres were fully characterized with several means including FT-IR, ¹³C NMR, TG-DSC and SEM. Metal crosslinking was introduced into the polymer microspheres to improve the temperature resistance by crosslinking the hydrolyzed polymer molecular chains. The results of optical microscopy and scanning electron microscopy demonstrated that a double crosslinked structure (DCS) was formed inside the Zr–AM/NVP/AMPS microspheres. It is regrettable that there is no three-dimensional network structure in the microspheres with single organic crosslinked structure (SCS). In aqueous solution, the DCS polymer microspheres were able to maintain long-term thermal stability for 150 days even at a high temperature of 140 °C. The microspheres with SCS can only be preserved for 5 days in high temperature aqueous solution at 140 °C. The TGA-DSC results indicated that the aerobic temperature capability of the DCS microspheres has been greatly improved compared with HPAM and SCS microspheres. The DCS microspheres with ultra-high temperature resistance will have broad application prospects in high temperature reservoirs.

Three monomers, acrylamide (AM), N-vinylpyrrolidone (NVP) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS), were crosslink-copolymerized in an inverse suspension system, obtaining crosslinked AM/NVP/AMPS microspheres.

[Study on the current status of smoking, intention of tobacco concession and related risk factors among 18-65-year olds patients with chronic diseases in Beijing]

Objective: To understand the status, attitude and related risk factors on smoking among 18-65 years old patients with hypertension, diabetes, dyslipidemia, chronic obstructive pulmonary disease (COPD) or asthma in Beijing. Methods: Data was gathered from the 2014 Beijing Non-communicable and Chronic Disease Surveillance Program. Multiple classified cluster sampling method was used and 19 815 participants aged 18-65 were sampled from 16 districts in Beijing. Results: Among all the 18 405 participants, male hypertensive patients showed a higher rate on current smoking than the other groups (χ(2)=17.695, P<0.001). Male patients with dyslipidemia had higher current smoking rate than the other groups (χ(2)=39.292, P<0.001). However, female patients with COPD or with asthma showed higher rate on current smoking than the other groups (χ(2)=6.276, P=0.012), (χ(2)=8.245, P=0.004). Among the smokers, hypertensive patients presented lower rate (χ(2)=20.487, P<0.001) on intention of smoking concession, than the other groups. Patients with COPD showed greater intention in quitting smoking (χ(2)=6.085, P=0.048), than the other groups. Male patients with diabetes (χ(2)=9.219, P=0.010) or dyslipidemia (χ(2)=13.513, P=0.001) who had stopped smoking tobacco appeared having higher rates in keeping the current status. Results from logistic regression analyses showed that smoking was the risk factor for hypertension (OR=1.17), dyslipidemia (OR=1.25), COPD (OR=1.78), and asthma (OR=1.57). Conclusions: Patients with certain kinds of chronic diseases showed higher rate of current smoking and lower rate of quitting. Cigarette consumption appeared an important risk factor for patients with hypertension, dyslipidemia, COPD, or asthma in Beijing.

Triceps motor branch transfer for isolated axillary nerve injury: Outcomes in 9 patients

INTRODUCTION

Triceps motor branch transfer has been used for more than ten years to restore deltoid function after axillary nerve injury. However, there have been few reports of the outcome of this procedure in isolated axillary nerve injury.

HYPOTHESIS

Triceps motor branch transfer could be an effective method to restore deltoid function for patients with isolated axillary nerve injury.

MATERIALS AND METHODS

Nine patients who underwent triceps motor branch transfer for treatment of isolated axillary nerve injury were followed up for at least 22 months. Shoulder abduction was assessed for all patients. The DASH outcome questionnaire was completed by every patient. Electrophysiological study was performed on 7 patients.

RESULTS

All patients regained≥90° (mean, 137°) shoulder abduction. Mean DASH score decreased from 35.2 before surgery to 13.1 at the last follow-up. There was no noticeable weakness of elbow extension in any patient.

DISCUSSION

Triceps motor branch transfer provided good results and may be a feasible alternative to nerve grafting for the treatment of complete isolated axillary nerve injury.

TYPE OF STUDY

IV, retrospective cohort study.

Comparative efficacy of five long-term weight loss drugs: quantitative information for medication guidelines

Quantitative information is scarce in current obesity medication guidelines, and they do not clearly reflect the differences in the efficacy characteristics among various drugs. This study quantitatively assessed the efficacy characteristics of five FDA-approved long-term weight loss drugs. Potentially eligible studies were obtained from public databases. Using the differences in the weight change from baseline between the drug group and the corresponding placebo group as the major indicator of efficacy, a time-effect model was established, and crucial pharmacodynamic parameters, such as the maximal efficacy, drug onset time and rate of body weight regain after the maximal efficacy point, were used to reflect the differences in efficacy among the five drugs. Finally, 50 reports (involving 43,443 participants) were included. After deducting the placebo effects, the maximal efficacies (95% CI) of orlistat (120 mg), lorcaserin, naltrexone-bupropion, phentermine-topiramate (PT, 7.5/46 mg) and liraglutide were -2.94 (-5.82, -1.27), -3.06 (-4.39, -1.71), -6.15 (-9.78, -3.25), -7.45 (-9.76, -3.88) and -5.50 (-10.62, -2.97) kg at weeks 60, 54, 67, 59 and 65 respectively, and their rates of body weight regain were 0.51, 0.48, 0.91, 1.27and 0.43 kg per year respectively. The 1-year dropout rates of orlistat, lorcaserin, naltrexone-bupropion, PT and liraglutide were 29.0, 40.9, 49.1, 34.9 and 24.3% respectively. In addition, a significant dose-effect correlation was observed for orlistat and PT. This study provides valid quantitative information for medication guidelines.

Computational methods for 2D materials: discovery, property characterization, and application design

The discovery of two-dimensional (2D) materials comes at a time when computational methods are mature and can predict novel 2D materials, characterize their properties, and guide the design of 2D materials for applications. This article reviews the recent progress in computational approaches for 2D materials research. We discuss the computational techniques and provide an overview of the ongoing research in the field. We begin with an overview of known 2D materials, common computational methods, and available cyber infrastructures. We then move onto the discovery of novel 2D materials, discussing the stability criteria for 2D materials, computational methods for structure prediction, and interactions of monolayers with electrochemical and gaseous environments. Next, we describe the computational characterization of the 2D materials' electronic, optical, magnetic, and superconducting properties and the response of the properties under applied mechanical strain and electrical fields. From there, we move on to discuss the structure and properties of defects in 2D materials, and describe methods for 2D materials device simulations. We conclude by providing an outlook on the needs and challenges for future developments in the field of computational research for 2D materials.