Characteristics of volatile flavor components in traditional fermented yak milk produced in different ecoregions of the Qinghai-Tibetan plateau.

The volatile flavor substances in traditional fermented yak milk samples collected from 5 ecoregions (A: coniferous forests and grasslands of the Qilian Qingdong Mountains; B: alpine grasslands surrounding the lakes in the Qiangtang Plateau; C: alpine shrubs and meadows of the Guoluo-Nagqu Highlands; D: coniferous forests along the alpine valley in East Tibet; E: shrubs and grasslands along the alpine valley in South Tibet) of the Qinghai-Tibetan plateau were comparatively analyzed. The relative percentage composition of volatile flavor substances varied among the different ecoregions. In samples collected from region E, more than 50% of the volatile flavor compounds were esters comprising mainly n-butyl acetate, butyl butyrate, and ethyl octanoate, and a considerable proportion of acetoin was found in samples from regions B and E. Greater proportions of 2-heptanone and 2-nonanone were observed in samples collected from regions A, C, and D compared with regions B and E.

[Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in chronic renal insufficiency rats].

Objective: To observe the effect of autophagy of tibial growth plate chondrocyte on apoptosis in chronic renal insufficiency (CRI) rats. Methods: Male 4-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=10); (2) CRI group: the left ureter was ligated to cause CRI (n=10). The urine from all the rats was collected 6 weeks after the operation and the total protein content was measured. Then all the rats were sacrificed and the concentrations of creatinine and urea nitrogen in intracardiac blood were detected. The proximal tibia were fixed and decalcified to prepare histological sections, and the number of chondrocytes of column cells in the proliferative area of tibia growth plate was observed by saffron O staining. The expression rate of protein Light Chain-3, an autophagy marker of chondrocytes, was detected by immunofluorescence. The apoptosis rate of chondrocytes was detected by the method of TUNEL assay. The level of glycogenin-1, a glycogen formation marker of chondrocyte was detected by immunohistochemistry in chondrocytes. Results: The 24 h urine total protein was higher in CRI group [(163.5±11.3) mg vs (38.6±9.8) mg, t=25.620, P<0.001]. The levels of blood creatinine [(67.3±16.2) µmol/L vs (28.4±11.5) µmol/L, t=5.974, P<0.001] and urea nitrogen [(16.4±6.4) mmol/L vs (4.8±2.0) mmol/L, t=5.198, P<0.001] were higher in CRI group. The number of chondrocytes of column cells in the proliferating area of tibia growth plate was lower in CRI group (4.2±2.1 vs 9.1±3.8, t=3.109, P=0.006). The expression rate of LC-3 protein in chondrocytes of CRI group was lower [(27.2±12.6)% vs (51.4±18.2)%, t=3.457, P=0.003]. The level of glycogenin-1 of chondrocytes in CRI group increased significantly (6.1±2.5 vs 3.5±1.8, t=2.669, P=0.016). The apoptosis rate of chondrocytes in CRI group also increased [(17.2±4.8)% vs (5.1±3.4)%, t=6.505, P<0.001]. Conclusion: Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in CRI rats, which might be caused by the failure of glycogen degradation in chondrocytes.

[Value of absolute quantification of myocardial perfusion by PET in detecting coronary microvascular disease in patients with non-obstructive coronaries].

Objective: To compare the incidence of coronary microvascular disease (CMVD) between patients with non-obstructive and obstructive coronary arteries. Methods: We retrospectively analyzed 97 patients with angina pectoris, who underwent the absolute quantitative PET examination of myocardial perfusion and coronary anatomy examination within 90 days. All patients were divided into two groups: non-obstructive group (72 cases, no stenosis ≥50% in all three coronary arteries) and obstructive group (25 cases, at least one coronary stenosis ≥50%; and at least one coronary stenosis<50%). Quantitative parameters derived from PET including rest myocardial blood flow (RMBF), stress myocardial blood flow (SMBF), coronary flow reserve (CFR) and cardiovascular risk factors were compared between the two groups. CMVD was defined as CFR<2.90 and SMBF<2.17 ml·min(-1)·g(-1). Results: Incidence of CMVD was significant higher in the non-obstructive coronary arteries of the obstructive group than in the non-obstructive coronary arteries of non-obstructive group (47.1% (16/34) vs. 25.5% (55/216), χ(2)=6.738, P=0.009) while incidence of CMVD was similar between non-obstructive and obstructive patients ((44% (11/25) vs. 33.3% (24/72), χ(2)=0.915, P=0.339). RMBF ((0.83±0.14) ml·min(-1)·g(-1) vs. (0.82±0.17) ml·min(-1)·g(-1)), SMBF ((2.13±0.60) ml·min(-1)·g(-1) vs. (1.91±0.50) ml·min(-1)·g(-1)) and CFR (2.59±0.66 vs. 2.36±0.47) were similar between the two groups (all P>0.05). Conclusions: CMVD can occur in non-obstructive coronary arteries in both patients with non-occlusive coronary arteries and patients with obstructive coronary arteries. Prevalence of CMVD is significantly higher in patients with obstructive coronary arteries than in patients with non-obstructive coronary arteries. The CMVD severity is similar between the two groups.

Characteristics of Pediococcus pentosaceus Q6 isolated from Elymus nutans growing on the Tibetan Plateau and its application for silage preparation at low temperature.

AIMS: Characteristics of a strain Pediococcus pentosaceus Q6 isolated from Elymus nutans growing on the Tibetan plateau and its effects on E. nutans silage fermentation stored at low temperature were investigated. METHODS AND RESULTS: Sugar fermentation pattern and growth profiles of the strain Q6 and its reference strain APP were characterized. The strain Q6 and APP were inoculated to E. nutans at ensiling respectively; and ensiled at different temperatures (10, 15 and 25°C) for 30, 60 and 90 days. The results indicated that Q6 could grow at pH 3·0 and at 4°C. In contrast to APP, Q6 could ferment mannitol, saccharose, sorbitol and rhamnose. Lower pH in Q6-treated silages fermented for 60 days at 10 and 15°C was found compared with the control and APP-treated groups. For the silages that were stored at 10 or 15°C, the greatest lactic acid content were detected in Q6-inoculated silages ensiled for 30 and 60 days respectively. There were no differences in pH and lactic acid content between Q6- and APP-treated silages ensiled at 10 and 15°C for 90 days respectively. CONCLUSIONS: Inoculation of the strain P. pentosaceus Q6 could improve fermentation quality of ensiled E. nutans at the early stage of ensiling stored at low temperature (10 or 15°C). SIGNIFICANCE AND IMPACT OF THE STUDY: The selection of P. pentosaceus inoculants for improving silage quality at low temperature, which provides a candidate strain to make high-quality silage in regions with frigid climate.

Characterization and identification of ferulic acid esterase-producing Lactobacillus species isolated from Elymus nutans silage and their application in ensiled alfalfa.

AIMS: Ferulic acid esterase (FAE)-producing Lactobacillus species isolated from ensiled Elymus nutans growing on the Qinghai-Tibetan plateau were characterized, and effects of their application to the alfalfa ensiling process and the evidence to synergic effect between cellulase and FAE were investigated. METHODS AND RESULTS: The results of 16S rRNA gene sequence and species-specific polymerase chain reaction amplification showed that two screened strains with high FAE activity were Lactobacillus plantarum A1 (LP) and L. brevis A3 (LBr). The optimum temperature and pH for the LP and LBr was 37°C and 6·4 respectively. The FAE exhibited a good stability at temperatures between 25 and 50°C and at pH values of 5·0-7·0. The two strains and a commercial cellulase (CE) were applied as additives to alfalfa silage. After 60 days of ensiling, the lactic acid in the control and CE groups were significantly lower than those of the other treatment groups. The neutral detergent fibre and acid detergent fibre contents in the LP group were significantly lower than those observed in the other groups. At the same time, the combination of CE and FAE-producing lactic acid bacteria synergistically improved the fermentation quality of the silage. CONCLUSIONS: The addition of the FAE-producing strain of L. plantarum A1 to alfalfa silage improved its fermentation quality, and reduced the fibre content of the silage. SIGNIFICANCE AND IMPACT OF THE STUDY: The screened homo-fermentative and FAE-producing strain of L. plantarum A1 could be a candidate strain in improving fermentation quality and fibre digestibility of ensiled forages.

[Experimental study on the improvement of Ilizarov transverse tibial bone transport and microcirculation reconstruction technique].

Objective: To observe the effect of traditional and modified Ilizarov transverse tibial bone transport on microvascular regeneration of lower limbs in dogs. Methods: After general anesthesia on 10 experimental dogs, traditional and modified transverse tibial bone transport were performed on both tibias respectively. The control group was treated with the traditional method (the periosteum and bone flap were completely isolated), while the experimental group was treated with the modified method (the fibular periosteum of the open window bone flap was retained). All the external fixators were pulled outwards at a speed of 1 mm every day from 5 days after operation;after one week, the external fixators were moved back every 3 days for one week. The situation of wounds and activity of lower limbs were observed. Simultaneously, the angiogenesis was observed by digital subtraction angiography (DSA) through femoral artery at different stages, and the density of vascular endothelial cells measured by local tissue sections. The data before and after the operation were compared with paired t test. Results: The operation was successfully completed in 10 experimental dogs, and all wounds healed about 1 week after the operation. There was no significant abnormality in lower limb movements in all dogs. Peripheral blood vessel area in middle leg of lower limb in 4 weeks and 8 weeks after operation was (5.9±0.4) mm(2) and (6.9±0.6) mm(2) in control group and it was (6.2±0.6) mm(2) and (8.0±0.6) mm(2) in experimental group, respectively; all were significantly improved than those before the operation ((5.0±0.4) mm(2), (4.9±0.4) mm(2), respectively) (F=446.457, 829.192, both P<0.05). There was no significant differences in vessel area between the two groups at the 4th week after operation (t=1.216, P=0.240), but there was significant difference at the 8th week after operation between the two groups (t=4.423, P=0.000). The percentage of vascular endothelial cells in stained cells under endoscopy was 4.42%±0.28% and 5.63%±0.53% in the control group at the 8th week; and in the experimental group, it was 5.35%±0.26% and 7.18%±0.25%, respectively;all were significantly elevated than those before the operation; and there were significant differences between the two groups (t=7.35, 8.30, both P<0.05). Conclusion: Transverse tibial bone transport and microvascular network regeneration technology can reconstruct the microvasculature below the calf of dogs; the method of window-opening osteotomy is improved to "door" type window-opening, it can retain the lateral periosteum of tibial crest and regenerate the microvasculature network more abundantly.

[Effect of primary cilia expression rate on Wnt/ß signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency young rats].

Objective: To observe the effect of primary cilia expression rate on Wnt/ß signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency (CRI) young rats. Methods: Male 2-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=6); (2) CRI group: the left ureter was ligated (n=6). Rats were sacrificed 2 weeks after the operation and the primary cilia expression rate of growth plate chondrocytes and key protein ß-catenin in Wnt/ß signaling pathway were observed in histological section of tibia specimen. Chondrocytes isolated from growth plate in two groups were cultured in vitro to P3 generation. The primary cilia expression rate and the level of ß-catenin were measured. The primary cilia expression rate was detected by agonists and antagonists Wnt/ß signaling pathway in chondrocytes of CRI group. The level of ß-catenin was detected by using serum-free culture and chloral hydrate to intervene chondrocytes in CRI group. Results: The primary cilia expression rate of growth plate chondrocytes in histological section of tibia specimen in CRI group was higher than that in Sham group [(17.5±7.7)% vs (8.7±3.6)%, t=3.237, P=0.005], and the level of ß-catenin was higher in CRI group (5.1±0.7 vs 1.9±0.8, t=6.731, P<0.001). The primary cilia expression rate of growth plate chondrocytes cultured in vitro in CRI group was higher than that in Sham group [(20.9±8.1)% vs (11.8±4.7)%, t=3.073, P=0.007], and the level of ß-catenin was higher in CRI group (0.49±0.12 vs 0.25±0.11, t=3.297, P=0.011). There was no significant change in primary cilia expression rate after intervention by using Wnt/ß signaling agonists and antagonists to change the level of ß-catenin [agonists group: (21.3±7.6)%, control: (20.6±6.8)%, antagonists group: (22.4±6.2)%, F=0.173, P=0.842]. The level of ß-catenin was significantly changed after intervention by using serum-free culture, chloral hydrate to alter the primary cilia expression rate (serum-free culture group: 0.61±0.23, control: 0.39±0.24, chloral hydrate group: 0.15±0.11, F=6.476, P=0.012). There was a positive correlation between the level of ß-catenin and primary cilia expression rate. Conclusion: The primary cilia expression rate and the level of Wnt/ß signaling pathway were higher in tibial growth plate chondrocytes in CRI rats model, and primary cilia might have positive regulatory effects on the Wnt/ß signaling pathway.

Relationship between Expression Changes of CB2R and Wound Age of Brain Contusion in Mice.

ABSTRACT: Objective To investigate the expression of cannabinoid type 2 receptor （CB2R） at different time points after brain contusion and its relationship with wound age of mice. Methods A mouse brain contusion model was established with PCI3000 Precision Cortical Impactor. Expression changes of CB2R around the injured area were detected with immunohistochemical staining, immunofluorescent staining and Western blotting at different time points. Results Immunohistochemical staining results showed that only a few cells in the cerebral cortex of the sham operated group had CB2R positive expression. The ratio of CB2R positive cells gradually increased after injury and reached the peak twice at 12 h and 7 d post-injury, followed by a decrease to the normal level 28 d post-injury. The results of Western blotting were consistent with the immunohistochemical staining results. Immunofluorescent staining demonstrated that the changes of the ratio of CB2R positive cells in neurons, CB2R positive cells in monocytes and CB2R positive cells in astrocytes to the total cell number showed a single peak pattern, which peaked at 12 h, 1 d and 7 d post-injury, respectively. Conclusion The expression of CB2R after brain contusion in neurons, monocytes and astrocytes in mice suggests that it is likely to be involved in the regulation of the biological functions of those cells. The changes in CB2R are time-dependent, which suggests its potential applicability as a biological indicator for wound age estimation of brain contusion in forensic practice.

Expression of Nrf2 in Different Cells after Human Cerebral Cortex Contusion.

ABSTRACT: Objective To observe the expression changes of nuclear factor-erythroid derived 2-related factors （Nrf2） in different cells at different time points after human cerebral cortex contusion, and to discuss its application in brain wound age estimation. Methods Thirty-six human brain tissues were selected, of which 6 were for control and 30 were cortical contusion at different time points post-injury, which were divided into 0-1 h, 3-6 h, 1-3 d, 5-7 d, and 10-14 d post-injury groups, with 6 cases in each group. Based on paraffin embedded sections, HE staining was used to observe the morphological changes post-injury, and double immunofluorescence staining was used to detect the expression of Nrf2 in neurons, astrocytes, and microglia. The number of positive cells was counted and statistical analysis was made. Results The number of neurons decreased 1-3 d post-injury. The expression of Nrf2 cells in neurons increased after injury, and the rate of positive cells peaked at 1-3 d post-injury. Glial cells were activated 1-3 d post-injury, and the activation peaked at 5-7 d post-injury. The cerebromalacia began to form at 10-14 d post-injury. Glial fibrillary acidic protein （GFAP） positive cells in mice increased gradually after injury and peaked at 5-7 d post-injury, while the proportion of Nrf2 in GFAP positive cells was relatively stable. After injury, ionized calcium-binding adapter molecule 1 （IBA1） positive cells increased and activated gradually. The expression proportion of Nrf2 in IBA1 positive cells increased gradually, reached its peak at 5-7 d post-injury, and then decreased. Conclusion The expression of Nrf2 in different cells involves in the biological function of different cells post-injury, and the dynamic expression of single cells has a time-dependent pattern. This may provide a new reference index for the wound age estimation of brain contusion in human.

Relationship between the Degeneration and Regeneration of Neuromuscular Junction and Wound Age during the Repair of Mouse Skeletal Muscle Contusion.

ABSTRACT: Objective To investigate the morphological changes in the degeneration and regeneration of neuromuscular junctions （NMJ） during the repair of mouse skeletal muscle contusion and discuss the correlation between the degeneration and regeneration of NMJ and wound age. Methods A total of 50 healthy adult male mice were randomly divided into 10 groups, including 9 experimental groups and 1 control group. Immunofluorescent staining was applied, and neurofilament was marked with neurofilament protein-H （NF-H）, presynaptic membrane was marked with synaptophysin （Syn）, presynaptic membrane was marked with acetylcholine receptor （AChR）. Morphological changes of NMJ regeneration at different time points after mouse skeletal muscle contusion were detected. Results The neurofilament and presynaptic membrane of NMJ at the junction of contusion zones began to degrade after contusion, and completed degradation at about 3 d post-injury. Then they gradually regenerated, roughly completing the regeneration at about 21 d and basically reaching the control group level. The ratio of presynaptic membrane quantity to presynaptic membrane quantity showed a trend of decreasing then rising and finally reaching the control level. Conclusion During the repair of mouse skeletal muscle contusion, the morphological changes and wound age of the NMJ at the junction of contusion zones have a close correlation, which is expected to be one of the biological indicators for forensic skeletal muscle wound age estimation.

Effects of addition of malic or citric acids on fermentation quality and chemical characteristics of alfalfa silage.

We studied the effects on alfalfa preservation and chemical composition of the addition of different levels of malic acid and citric acid at ensiling as well as the utilization efficiency of these 2 organic acids after fermentation. Alfalfa was harvested at early bloom stage. After wilting to a dry matter content of approximately 40%, the alfalfa was chopped into 1- to 2-cm pieces for ensiling. Four levels (0, 0.1, 0.5, and 1% of fresh weight) of malic acid or citric acid were applied to chopped alfalfa at ensiling with 4 replicates for each treatment, and the treated alfalfa forages were ensiled for 60 d in vacuum-sealed polyethylene bags (dimensions: 200 mm × 300 mm) packed with 200 to 230 g of fresh alfalfa per mini silo and an initial density of 0.534 g/cm3. The application of malic or citric acids at ensiling for 60 d led to lower silage pH than was observed in the control silage (0% of malic or citric acids). Application of the 2 organic acids led to higher lactic acid concentration in alfalfa silage than in the control silage except with the application rate of 1% of fresh weight. Silages treated with both organic acids had lower nonprotein nitrogen concentrations than the control silages, and the nonprotein nitrogen concentrations in ensiled forages decreased with the increase in malic or citric acid application rates. The application of the 2 organic acid additives led to lower saturated fatty acid proportions and higher polyunsaturated fatty acid proportions in ensiled alfalfa than in the control silage. The amount of malic and citric acids degraded during ensiling of alfalfa was 1.45 and 0.63 g, respectively. At the application rate of 0.5% of fresh weight, residues of malic acid and citric acid in alfalfa silage were 11.1 and 13.6 g/kg of dry matter. These results indicate that including malic or citric acids at the ensiling of alfalfa effectively improved silage fermentation quality, limited proteolysis, improved fatty acid composition of the ensiled forage, and could provide animals with additional feed additives proven to promote animal performance. However, when the application rate of both organic acids reached 1%, the concentration of lactic acid in silages decreased notably. Additionally, 0.5 and 1% application rates also increased the yeast count in ensiled alfalfa.

Effect of Lactobacillus inoculants and forage dry matter on the fermentation and aerobic stability of ensiled mixed-crop tall fescue and meadow fescue.

This study evaluated the effects of Lactobacillus plantarum with or without Lactobacillus buchneri on the fermentation and aerobic stability of mixed tall fescue (Festuca arundinacea Schreb) and meadow fescue (Festuca pratensis Huds.) silage ensiled at different dry matter (DM) contents. The first cut was harvested at boot stage and second-cut grasses were harvested when 30- to 35-cm tall. Four DM content treatments of the first cut were 17.9, 24.9, 34.6, and 48.7%; and of the second cut were 29.1, 36.3, 44.1, and 49.2%. Chopped grasses at each DM content were treated with (1) deionized water (control), (2) Lb. plantarum MTD-1 (LP), or (3) a combination of Lb. plantarum MTD-1 and Lb. buchneri 40788 (LP+LB). The application amount of each inoculant to the fresh forage was 1 × 10(6) cfu/g. Grasses were ensiled in vacuum-sealed polyethylene bags containing 150 g of DM for 60 d, with 4 replicates for each treatment. Silages inoculated with LP+LB had greater pH compared with untreated or LP-treated silages. Lactate was greater in LP silage than control or LP+LB silages. As silage DM increased, lactate in untreated and LP-treated silages decreased, but increased in LP+LB-treated silage. Acetate concentration decreased with increased DM in all silages. The LP+LB-treated silage had the longest and control silage the shortest aerobic stability for both harvests. The greatest values in aerobic stability were observed in silages with highest DM content. In this study, aerobic stability of grass mixes ensiled between 18 and 44% DM content increased as the percentage of DM increased. The LP and LP+LB inoculants improved aerobic stability of silages harvested between 18 and 44% DM content.

Effects of plant enzyme inactivation or sterilization on lipolysis and proteolysis in alfalfa silage.

This experiment studied the contribution of plant enzymes and microbial activity on lipolysis and proteolysis in ensiled alfalfa. Before ensiling, the wilted alfalfa was treated with plant enzyme inactivation by autoclaving or with sterilization by γ-ray irradiation. The treated alfalfa was then inoculated with commercial lactic acid bacteria inoculants and ensiled for 40 d. Alfalfa without treatment was ensiled as the control. The content of total fatty acid (FA) after ensiling decreased 43% in the control silage and 28% in the γ-ray-treated silage, but did not change in the autoclave-treated silage. Among the major FA (C16:0, C18:2n-6, C18:3n-3), a considerable increase was observed in proportion of C16:0 in the control silage as compared with fresh alfalfa; conversely, decreases in proportions of C18:2n-6 and C18:3n-3 occurred during ensilage. Silage treated with γ-ray radiation at ensiling had a smaller proportion of C16:0 and greater proportions of C18:2n-6 and C18:3n-3 than control silage. Autoclave treatment further decreased proportions of C16:0 and most of the other FA, and increased C18:2n-6 and C18:3n-3 proportions in comparison with γ-ray treatment. Proportions of C16:0, C18:2n-6, C18:3n-3 and other detected FA (except for the proportion of C15:0) did not differ between fresh forage and autoclave-treated silage. Remarkably, smaller nonprotein nitrogen content was observed in the autoclave-treated silage compared with the γ ray-treated silage or the control silage. These results indicated that an extensive lipolysis occurred during ensiling of alfalfa, and plant enzymes played a major role in lipolysis and proteolysis.

Short communication: Characteristics of proteolytic activities of endo- and exopeptidases in alfalfa herbage and their implications for proteolysis in silage.

The pH optimum and thermostability of both exopeptidases and endopeptidases were investigated in this study to elucidate the possible role of plant proteases in proteolysis during ensiling of alfalfa herbage. Proteolytic activities of 4 classes of endopeptidases (i.e., serine, metallo, aspartic, and cysteine peptidase) and 5 classes of exopeptidases (i.e., aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase) were examined within pH values of 3 to 9, and within temperatures from 20 to 90°C. Serine and metalloproteases, the principal endopeptidases that hydrolyzed most of the protein to nonprotein nitrogen in alfalfa silage, had optimum activities at pH 4. Among the major exopeptidases contributing protein degradation in ensiled alfalfa, dipeptidase and tripeptidyl-peptidase had stable activities between pH 4 and 6, and carboxypeptidase activity was optimal at pH 5. The optimum temperature for most peptidase activities was 40°C. Proteolytic activities of both endo- and exopeptidases increased with the elevation of incubating temperature from 20 to 40°C. The pH value in well-preserved alfalfa silage is often above 4.0, and the temperatures in the ensiled mass range from 25 to 40°C. Therefore, high proteolytic activities between pH 4 and 6 and the temperature range of ensiled alfalfa suggest that plant peptidases play a role in hydrolyzing protein during prolonged storage.

Author Correction: Nitrosative stress induces downregulation of ribosomal protein genes via MYCT1 in vascular smooth muscle cells.

Correction to: European Review for Medical and Pharmacological Sciences 2021; 25 (18): 5653-5663-DOI: 10.26355/eurrev_202109_26784-PMID: 34604957, published online on 30 September, 2021. After publication, the authors applied to add another corresponding author. Therefore, both Dr. Xiaosun Guo and Dr. Fan Jiang are the corresponding authors of this article. There are amendments to this paper. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/26784.

An acoustic rectifier.

The detection of acoustic signals is of relevance for a range of practical applications, for example in medical diagnostics. However, whereas rectification of electric current and other energy forms such as thermal flux has been demonstrated, acoustic rectification has not yet been achieved. Here, on the basis of the earlier theoretical proposal of an 'acoustic diode', we present the first experimental demonstration of a rectified energy flux of acoustic waves. A one-dimensional acoustic rectifier is fabricated by coupling a superlattice with a layer of ultrasound contrast agent microbubble suspension. A significant rectifying effect is observed within two frequency bands at locations that agree well with theoretical predictions. Following optimization of the concentration of the microbubble suspension, rectifying ratios can be as high as ~10(4). This realization of an acoustic rectifier should have substantial practical significance, for example in the focusing of ultrasound in medical applications.

Contribution of exopeptidases to formation of nonprotein nitrogen during ensiling of alfalfa.

The experiment was conducted to investigate the exopeptidase classes in alfalfa (Medicago sativa L.) leaves, and to determine their contribution to the formation of nonprotein nitrogen (NPN) components during ensiling. Six classes of inhibitors that included bestatin (aminopeptidase inhibitor), potato carboxypeptidase inhibitor (PCI, carboxypeptidase inhibitor), 1,10-phenanthroline (dipeptidase inhibitor), diprotin A (dipeptidyl-peptidase inhibitor), butabindide (tripeptidyl-peptidase inhibitor), and dipeptide Phe-Arg (peptidyl-dipeptidase inhibitor) were used. To determine the contribution of each exopeptidase to the formation of NPN products, aqueous extracts of fresh alfalfa were fermented to imitate the proteolytic process of ensiled alfalfa and to ensure that each class of exopeptidase inhibitor would have immediate contact with the proteases in the alfalfa extract. Five classes of exopeptidases; namely, aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase, were shown to be present in alfalfa leaves, each playing a different role in alfalfa protein degradation. Aminopeptidase, carboxypeptidase, and dipeptidase were the main exopeptidases contributing to the formation of NH(3)-N. Among the 5 exopeptidases, tripeptidyl-peptidase appeared to be the principal exopeptidase in hydrolyzing forage protein into peptides, whereas carboxypeptidase and dipeptidase appeared to be more important in contributing to the formation of amino acid-N. Dipeptidyl-peptidase and tripeptidyl-peptidase did not play a role in the formation of NH(3)-N or amino acid-N. Dipeptidase, carboxypeptidase, and tripeptidyl-peptidase were the principal exopeptidases for hydrolyzing forage protein into NPN during ensilage, and treatment with a mixture of the 5 inhibitors reduced the total NPN concentration in the fermented alfalfa extract to about 45% of that in the control after 21 d of fermentation.

Nitrosative stress induces downregulation of ribosomal protein genes via MYCT1 in vascular smooth muscle cells.

OBJECTIVE: In our previous genomic studies in human intracranial aneurysms, we observed downregulations in the expression of a number of ribosomal protein genes and the c-Myc-related gene MYC target 1 (MYCT1). So far there is no information about the roles of MYCT1 in vascular cells. Our study aims to investigate the functional roles of MYCT1 in vascular smooth muscle cells (SMCs). MATERIALS AND METHODS: Primary SMCs were isolated from rat thoracic aorta and cultured in vitro. The mRNA and protein expressions were determined by real-time PCR and western blot respectively. Apoptosis was detected by measuring caspase 3/7 activity. Collagen production was determined with ELISA. RESULTS: Using PCR, we validated our previous genomic data showing that the expressions of MYCT1 and ribosomal protein genes were decreased in human aneurysm tissues. In vascular SMCs, we showed that nitrosative stress downregulated the expression of both MYCT1 and ribosomal proteins. Knockdown of MYCT1 mimicked the effects of nitrosative stress on ribosomal protein expressions, whereas overexpression of MYCT1 blunted the effects of nitrosative stress. MYCT1-dependent downregulation of ribosomal proteins compromised the protein translational capacity of the cells for collagen production. Moreover, the endogenously expressed MYCT1 in vascular SMCs was involved in maintaining normal cellular functions including survival, proliferation and migration. CONCLUSIONS: MYCT1-dependent gene regulation may, at least partly, explain the downregulated expressions of ribosomal proteins observed in human intracranial aneurysms. It is suggested that MYCT1 may represent a novel molecular target for counteracting the decreased activity of aneurysmal SMCs for tissue repairmen/regeneration.

[Loss of autophagy in condylar chondrocytes causes increased apoptosis rate in temporomandibular joint osteoarthritis of rats].

Objective: To observe the effect of autophagy of condylar chondrocytes on apoptosis in temporomandibular joint osteoarthritis (TMJOA) of rats. Methods: Fourty male 2-month-old SPF SD rats were equally divided into sham group (n=20) and experimental group (n=20). UAC metal prosthesis was cemented to the left incisors of maxilla and mandible of the rats in experimental group rats. After 8 weeks, all rats were sacrificed and the temporomandibular joint was taken. Two groups of rat condylar chondrocytes were extracted and cultured in vitro to the third generation. Immunofluorescence technique was used to detect the levels of collagen Ⅱ and matrix metalloproteinase-13 (MMP-13) in chondrocytes. The level of light chain-3 (LC-3), an autophagy marker of chondrocytes, was detected. Immunohistochemical technique was used to detect the level glycogenin-1, a glycogen formation marker of chondrocyte, was detected. The level of caspase-3, an apoptosis marker of chondrocyte, was also detected. Tunel technique was used to detect the apoptosis rate of the two groups at 72 h. Cracking cell extraction of total protein, Western-blotting (WB) technology to detect the levels of collagen Ⅱ, MMP -13, LC-3, glycogenin-1, caspase-3 and make gray analysis. Results: Compared with sham group, the level of collagen Ⅱ decreased, MMP-13 increased, LC-3 decreased, glycogenin-1 increased and caspase-3 increased in experimental group. The apoptosis rate of chondrocytes in experimentaal group [ (17.3±4.4) %] at 72h was higher than that in control group [ (5.6±2.1) %](t=10.732, P<0.001) .WB bands gray statistical results show that the level of collagen Ⅱ in chondrocytes of experimental group (0.43±0.21) was lower than that of control group (0.71±0.26) (t=2.409, P=0.043) , the level of MMP-13 in chondrocytes of experimental group (0.73±0.31) was higher than that of control group (0.24±0.10) (t=3.364, P=0.010) , the level of LC-3 in chondrocytes of experimental group (0.09±0.04) was lower than that of control group (0.39±0.18) (t=3.638, P=0.007) , the level of glycogenin-1 in chondrocytes of experimental group (0.68±0.30) was higher than that of control group (0.29±0.17) (t=2.529, P=0.035) , the level of caspase-3 in chondrocytes of experimental group (0.19±0.08) was higher than that of control group (0.05±0.02) (t=3.796, P=0.005) . Conclusions: The level of autophagy of condylar chondrocytes in temporomandibular joint of rats decreased, glycogen accumulation increased, the rate of chondrocyte apoptosis increased, and the number of chondrocytes decreased, resulting in degeneration of condylar cartilage tissue.

[Effect of treatment of infant parotid hemangioma with no response to oral propranolol].

Hemangioma is the most common vascular tumor in infantile period, and propranolol is the first choice, but there are still a few patients with poor curative effect. Seven cases of infant parotid hemangioma with no response to oral propranolol were treated with transcatheter arterial sclerosing embolization combined with cortisol and satisfactory results achievod. The treatment and efficacy are disccused in this paper.