[Epidemiological trends of schistosomiasis in Poyang County of Jiangxi Province from 2004 to 2020 based on the Joinpoint regression model]

OBJECTIVE

To analyze the dynamic changes of schistosomiasis in Poyang County of Jiangxi Province from 2004 to 2020, so as to provide insight into the development of the schistosomiasis elimination strategy.

METHODS

Schistosomiasis control data were captured from Poyang County from 2004 to 2020, and the epidemiological data of schistosomiasis were collected from national schistosomiasis surveillance sites in Poyang County from 2005 to 2020. The endemic status of schistosomiasis was analyzed in Poyang County from 2004 to 2020, and a Joinpoint regression analysis was performed to investigate the trends of schistosomiasis in Poyang County from 2004 to 2020.

RESULTS

The sero-prevalence and egg-prevalence of human Schistosoma japonicum infections reduced from 24.39% (24 976/102 397) and 4.53% (259/5 721) in 2004 to 5.37% (2 421/45 100) [annual percent change (APC) = average annual percent change (AAPC) = -8.64%] and 0 (0/3 963) in 2020 (APC = AAPC = -32.07%) in Poyang County, and the trends were both significant (both P < 0.01). The sero-prevalence of S. japonicum infections reduced from 1.21% (294/24 332) in bovines in 2013 to 0.58% (35/5 999) in 2020 in Poyang County, with one turning point (AAPC = -8.20%, P > 0.05). There were no townships or villages with emerging snail habitats in Poyang County from 2004 to 2020, and there were three turning points of trend in the proportion of snail areas detected in total snail areas (AAPC = -2.30%, P > 0.01). The sero-prevalence and adjusted prevalence of S. japonicum infections reduced from 60.82% (742/1 220) and 10.16% (124/1 220) in local residents in 2005 to 5.73% (70/1 221) and 0 in 2020 in national schistosomiasis surveillance sites of Poyang County, and the trends for sero-prevalence (APC = AAPC = 17.47%, P < 0.01) and adjusted prevalence of S. japonicum infections (APC = AAPC = -44.92%, P < 0.01) were both statistically significant. S. japonicum infections were identified in 10 (2005) and 2 local livestock (2007), with prevalence of 10.00% (10/100) and 13.33% (2/15), respectively, and S. japonicum infections were detected in snails in 2008 and 2009; however, no positive samples of mixed O. hupensis were detected by loop-mediated isothermal amplification.

CONCLUSIONS

The endemic situation of schistosomiasis control had remarkably reduced in Poyang County from 2004 to 2020; however, there are still challenges for consolidating schistosomiasis control achievements and even elimination of schistosomiasis.

Synergistic Effect of Hydrogen Bonds and Chemical Bonds to Construct a Starch-Based Water-Absorbing/Retaining Hydrogel Composite Reinforced with Cellulose and Poly(ethylene glycol)

The hydrogel prepared by graft copolymerization of starch (ST) and acrylamide (AM) is a commonly used absorbent material; however, due to their irregular network structure and a limited number of hydrophilic groups, starch-based hydrogels have poor water absorption and water retention. To overcome this, here, we provide a new preparation method for starch-based hydrogels. Using cerium ammonium nitrate (CAN) as an initiator, the starch-acrylamide-cellulose (CMC)/poly(ethylene glycol) (S-A-M/PEG) superabsorbent hydrogel was prepared by graft copolymerization. The starch-acrylamide-cellulose/poly(ethylene glycol) hydrogel network is constructed through the synergistic effect of hydrogen bonds and chemical bonds. The experimental results showed that the starch-acrylamide-cellulose/poly(ethylene glycol) superabsorbent hydrogel has a complete network structure that does not easily collapse due to its superior mechanical properties. The water swelling rate reached 80.24 times, and it reached 50.61% water retention after 16 days. This hydrogel has excellent water-absorbing and water-retaining properties, biocompatibility, and degradability, making it useful for further studies in medical, agricultural, and other fields.

Ceramic Inlay Bonded Interfaces in Minimally Invasive Preparations: Damage and Contributing Mechanisms in Sliding Contact

BACKGROUND

In the preparation of inlay cavities, a choice must be made between conventional standard and minimally invasive preparation designs; in the long run, this choice can affect the integrity of the bonded interface.

PURPOSE

To evaluate the effect of minimally invasive cavity preparation designs on the extent and contributing mechanisms of damage to ceramic inlay bonded interfaces.

METHODS AND MATERIALS

Tooth blocks with 90°, 120° and 75° marginal angles were prepared, representing tooth cavities with conventional standard and minimally invasive preparations with large divergence and convergence angles and bonded to monolithic ceramic (IPS e.max CAD). Vickers indentations were placed at various distances from the bonded interface. The indentation morphology and crack length were observed. Reciprocating wear tests were performed on the bonded interface with a 20-newton (N) vertical load. The wear depth and wear-scar morphology were characterized after increments of cyclic sliding contact.

RESULTS

The 120° group exhibited longer indentation cracks in the ceramic, whereas the 75° group showed larger indentations in the enamel when compared to the 90° group (p<0.001). Consistent with the weaker edge crack resistance, the 120° group experienced the greatest wear (p=0.008), and the wear depth in the enamel of the 75° group exceeded that of the 90° group (p<0.001) in the early stage (5×102 cycles). However, no significant difference in the wear depth (p>0.147) and morphology were found at the later wear stage among the three groups.

CONCLUSION

Within the limitations of this study, minimally invasive preparations with 120° and 75° marginal angles can result in early sever damage at the ceramic inlay bonded interface but show comparable wear behaviors to the conventional 90° group at the later stage.

[Identification of factors affecting Oncomelania hupensis density in Eastern Dongting Lake regions]

OBJECTIVE

To evaluate the impact of water pollutants, water levels and meteorological factors on the Oncomelania hupensis density in Eastern Dongting Lake regions, so as to provide insights into schistosomiasis control.

METHODS

O. hupensis snails were surveyed using a systematic sampling method in snail-infested marshlands in Eastern Dongting Lake regions from 2007 to 2014, and data pertaining to water pollutants, water levels and meteorological factors were collected. The duration of submergence and the date of the start of submergence were calculated. The snail density and its influencing factors were descriptively analyzed, and a linear mixed model was generated to examine the impacts of variables on the snail density. In addition, smooth curves were fitted to investigate the relationship between snail density and variables.

RESULTS

The snail density appeared a fluctuation in Eastern Dongting Lake regions during the period from 2007 to 2014, with the highest density on October, 2010 (52.79 snails/0.1 m²) and the lowest density on January 2009 (2.15 snails/0.1 m²). Linear mixed-model analysis showed that permanganate index, total phosphorus and the date of the start of submergence affected the snail density (t = 6.386, -2.920 and -3.892, all P values < 0.01). Smooth curve analysis revealed that the associations of the snail density with the permanganate index and total phosphorus appeared an approximately quadratic curve. After the end of April, the earlier date of the start of submergence resulted in a higher snail density.

CONCLUSIONS

Permenganate index, total phosphorus and the date of the start of submergence affect the O. hupensis snail density in Eastern Dongting Lake regions.

Establishment and verification of a nomogram for predicting severe acute pancreatitis

OBJECTIVE

The purpose of this study was to establish a nomogram for predicting the severity of acute pancreatitis (AP) and verify its predictive value.

PATIENTS AND METHODS

A total of 571 AP patients received by Ordos Central Hospital from January 2015 to December 2018 were included in this study. According to the 2012 Revised Atlanta classification, the included subjects were classified into severe AP (SAP) group and non-severe AP (NSAP) group [including patient with mild AP (MAP) and moderately SAP (MSAP)]. The baseline characteristics, imageological data and pathological data within 24 h after the disease onset between the two groups were analyzed using One-way analysis of variance (one-way ANOVA). R language was used for establishing a predictive nomogram, whose performance was verified by clinical data of 150 AP cases collected from December 2018 to December 2019.

RESULTS

One-way ANOVA shows that SAP and NSAP patients show significant differences in sex, calcium ions, creatinine, neutrophils ratio, lymphocytes ratio and eosinophils ratio (p<0.05). A predictive nomogram was accordingly established using the six indicators. Validation on this predictive nomogram showed high internal validation concordance index (C-index) of 0.69 (95% CI, 0.64-0.74), and high external validation C-index of 0.71 (95% CI, 0.67-0.76).

CONCLUSIONS

This nomogram can be used as a clinical tool to predict the severity of SAP.

Multiple Intermolecular Interaction to Improve the Abrasion Resistance and Wet Skid Resistance of Eucommia Ulmoides Gum/Styrene Butadiene Rubber Composite

A rubber composite was prepared by using methyltriethoxysilane (MTES) to modify silica (SiO2) and epoxidized eucommia ulmoides gum (EEUG) as rubber additives to endow silica with excellent dispersion and interfacial compatibility under the action of processing shear. The results showed that compared with the unmodified silica-reinforced rubber composite (SiO2/EUG/SBR), the bound rubber content of MTES-SiO2/EEUG/EUG/SBR was increased by 184%, and its tensile strength, modulus at 100% strain, modulus at 300% strain, and tear strength increased by 42.1%, 88.5%, 130.8%, and 39.9%, respectively. The Akron abrasion volume of the MTES-SiO2/EEUG/EUG/SBR composite decreased by 50.9%, and the wet friction coefficient increased by 43.2%. The wear resistance and wet skid resistance of the rubber composite were significantly improved.

In-situ formed Cyclodextrin-functionalized graphene oxide / poly (N-isopropylacrylamide) nanocomposite hydrogel as an recovery adsorbent for phenol and microfluidic valve

Phenolic compounds are important industrial raw materials for various industrial applications, but phenol-containing wastewater creates significant environmental and biological hazards. To address these issues, a three-dimensional network graphene oxide-cyanoethyltriethoxysilane-β-cyclodextrin/poly (N-isopropylacrylamide) (GO-CTES-β-CD/PNIPAM) nanocomposite hydrogel as a phenol recovery adsorbent is prepared herein by in-situ polymerization. Double graft modification on the graphene oxide (GO) via the silane coupling agent 2-cyanoethyltriethoxysilane (CTES) and single (6-tetraethylenepentamine-6-deoxy)-β-cyclodextrin (NH-β-CD) compensated the loss of the active sites on both GO and N-isopropylacrylamide (NIPAM), and the hydrogel shows excellent mechanical properties as the chemical crosslinking and physical entanglement of the two components. Consequently, the composite hydrogel achieved an adsorption capacity of 131.64 mg·g^-1 for the common environmental toxin 4-NP. After five repeated adsorption-desorption cycles, the hydrogel retained 74% of the initial 4-NP removal ratio. The adsorption results followed pseudo-first-order kinetics, corresponding to heterogeneous multilayer adsorption, which was regulated by a combination of surface adsorption and intra-particle diffusion mechanisms. In general, the nanocomposite hydrogel shows promising application in the field of recycling phenols from wastewater. Also, high photothermal conversion and temperature-sensitive properties are also demonstrated, which makes the hydrogel possessing great potential to be applied in smart microvalves.

[miR-let-7c-5p inhibits invasion and migration of bladder cancer cells by targeting HMGA2]

OBJECTIVE

To investigate whether miR-let-7c-5p inhibits invasion and migration of bladder cancer cells by regulating HMGA2.

METHODS

We used bioinformatics methods to determine the key genes of miR-let-7c-5p. RT-qPCR and Western blotting were used to detect the expressions of miR-let-7c-5p mRNA and HMGA2 protein in bladder cancer and adjacent tissues. With human normal bladder SV-HUC-1 cells as the control, we detected the expression levels of miR-let-7c-5p mRNA and HMGA2 protein in bladder cancer cell lines T24, UM-UC-3 and 5637 with RT-qPCR and Western blotting. We observed the effects of miR-let-7c-5p upregulation (by transfection with a miR-let-7c-5p mimic), miR-let-7c-5p downregulation (using a miR-let-7c-5p inhibitor), and knockdown of both HMGA2 and miR-let-7c-5p on invasion, migration and expressions of epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, N-cadherin, vimentin, and Snail) in UM-UC-3 cells. Dual luciferase assay, RT-qPCR and Western blotting were used to verify the targeting relationship between miR-let-7c-5p and HMGA2.

RESULTS

HMGA2 was identified as one of the target genes of miR-let-7c-5p. Compared with the adjacent tissues, bladder cancer tissues showed a significantly decreased expression of miR-let-7c-5p and an increased expression of HMGA2 protein (P < 0.05). In UM-UC-3 cells, the expression of miR-let-7c-5p was significantly reduced and that of HMGA2 was significantly increased as compared with those in SV-HUC-1 cells (P=0.001). Up-regulating miR-let-7c-5p expression significantly lowered the invasion and migration abilities of UM-UC-3 cells, and down-regulating miR-let-7c-5p expression obviously promoted the invasion and migration of UM-UC-3 cells (P < 0.05). Knockdown of both miR-let-7c-5p and HMGA2 expression significantly lowered the invasion and migration (P < 0.05) and inhibited the expressions of EMT-related proteins of UM-UC-3 cells (P < 0.05).

CONCLUSION

miR-let-7c-5p inhibits EMT of bladder cancer UM-UC-3 cells by targeting HMGA2, thereby inhibiting the cell invasion and migration.

[Alteration on hepatocyte nuclear factor 1α expressions and significance in the process of occurrence and development of liver inflammation and fibrosis in patients with chronic hepatitis B]

Objective: To investigate the relationship between the expression of hepatocyte nuclear factor-1 α (HNF-1α) and the occurrence and development of liver inflammation and fibrosis in liver tissues of patients with chronic hepatitis B. Methods: Sixty-four patients with chronic hepatitis B who were diagnosed and treated in our hospital from 2011 to 2018 were selected. All patients underwent ultrasound-guided aspiration liver biopsy. The pathological results of liver biopsy were collected for inflammation grading and fibrosis staging. The liver puncture biopsies was collected by paraffin sectioning. The expression of HNF1α in the liver tissue was detected by immunohistochemical staining. Mantel-Haenszel χ(2) test was used for bidirectional ordered grouping data, and Spearman's rank-correlation test was used for rank correlation analysis. Results: There were varying degrees of inflammatory necrosis and fibrosis in the liver tissues of patients with chronic hepatitis B. There was a linear relationship between the expression of HNF1α and the level of inflammation in liver tissues (χ (2)(MH) = 40.70, P < 0.05). The expression of HNF1α in liver tissues of patients with chronic hepatitis B was decreased with the increase of liver inflammation. The expression intensity of HNF1α was negatively correlated with the inflammation grade (r(s) = -0.815, P < 0.05). There was a linear relationship between the expressions of HNF1α and the degree and stage of liver fibrosis (χ (2)(MH) = 31.95, P < 0.05). The expression level of HNF1α in liver tissue was gradually decreased with the aggravation of liver fibrosis. The expression intensity of HNF1α was negatively correlated with fibrosis stage (r(s) = -0.713, P < 0.05). Conclusion: HNF1α is closely related to the occurrence and development of liver tissue inflammation and fibrosis, and is expected to be a sensitive indicator for evaluating the level of liver tissue inflammation and fibrosis in patients with chronic hepatitis B. In addition, its down-regulation may be involved in the process of occurrence and development of liver inflammation and liver fibrosis, and may become a new target for the treatment of chronic hepatitis B.

[Current status of HIV self-testing application]

HIV self-testing is a key measure and strategy to expand the coverage of HIV testing in key populations, which has great value in application and high acceptance in key populations. The World Health Organization (WHO) issued the Guidelines on HIV self-testing and partner notification in 2016 to support the application of HIV self-testing and provide specific guidance for countries and organizations to develop corresponding public health policies for the purpose of improving the accessibility and utilization of HIV diagnostics. HIV self-testing has been promoted in many countries and has achieved great results. This article provides an overview of the current domestic and international HIV self-testing policies, intervention models, the use of self-testing kits, the accuracy of self-testing kits, and the application of pre- and post-testing counseling services to provide reference for the further improvement of HIV self-testing in China.

[Changing trends of HIV testing and HIV self-testing in men who have sex with men on a gay social networking app]

Objective: To understand the changing trends of HIV testing rates, with a focus on HIV self-testing, and to evaluate the impact of HIV self-testing on expanding HIV testing among MSM in China in past few years. Methods: MSM were recruited online nationwide via a gay social networking app (Blued) from 2013 to 2016 and 2018. The survey collected information about socio-demographic backgrounds, sexual behaviors, and prior HIV testing experiences, including HIV self-testing. Trend analyses were conducted. Results: Respectively, 1 342, 1 424, 1 173, 2 105 and 699 MSM were recruited nationwide from 2013 to 2016, and in 2018. The mean age was (30.6±6.6)years in 2013 and showed a decreasing trend afterwards. The HIV testing rate was 60.0% (805/1 342) in 2013 and there was a rising trend from 2013 to 2016, and 2018 (trend Z =19.3, P <0.001), reaching a peak at 77.3% (540/699) in 2018. Further, the HIV self-testing rate increased from 19.3% (259/1 342) in 2013 to 58.1% (406/699) in 2018 (χ²=237.5, P <0.001). The proportion of MSM who had HIV self-testing among prior HIV testers significantly increased from 32.2% (259/805) to 75.2% (406/540) during the study period (trend Z =14.3, P <0.001). Conclusions: The HIV testing rate, HIV self-testing rate and proportion of men who had HIV self-testing among former HIV testers among web-based Chinese MSM showed substantial increases from 2013 to 2016,and 2018. This suggests that HIV self-testing may have a significant effect on the expansion of HIV testing coverage in MSM, and has important public health implications for HIV/AIDS prevention in China.

[Strengthening the safety of phakic intraocular lens implantation for myopia and astigmatism]

With the improvement of intraocular lens materials and function design, phakic intraocular lens implantation has been widely carried out for myopia and astigmatism and achieved satisfactory clinical results at home and abroad. The range of corrected myopia diopters has gradually changed from previous super-high and high myopia to low myopia. With the expansion of the scope of indications and applications, it is necessary to strengthen the standardization of phakic intraocular lens implantation for myopia and astigmatism, and it is particularly important to further improve its safety and quality control. This article discusses how to rationally select indications, increase the accuracy of the design, and effectively prevent surgical complications, providing a reference for further improvement of clinical safety and quality control. (Chin J Ophthalmol, 2021, 57: 86-89).

[Middle and long-term follow-up of 101 children with giant coronary artery aneurysm of Kawasaki disease]

Objective: To summarize the clinical features, middle-and long-term prognosis of Kawasaki disease (KD) with giant coronary artery aneurysm (GCAA). Methods: In this retrospective cohort study, a cross-sectional analysis was conducted on 101 KD children with GCAA in the KD with GCAA database established by Beijing Children's Hospital, Capital Medical University in 2004. GCAA was diagnosed as coronary artery absolute lumen diameter ≥8.0 mm. All patients were followed up regularly. The endpoint was the time of last follow-up or the death time. T test or χ² test was used for comparison between groups. Results: A total of 101 KD children with GCAA were enrolled, including 82 males (81.2%) and 19 females (18.8%). The age of disease onset was 2.5 (1.0, 4.5) years. The follow-up duration was 4.5 (2.7, 7.5) years, with a longest of 19 years. All children received routine treatment with aspirin and warfarin, and clopidogrel was added in severe cases. At the end of follow-up, 13 cases (12.9%) had cardiac enlargement, 11 cases (10.9%) developed heart failure, 13 cases (12.9%) experienced myocardial infarction, 2 cases (2.0%) underwent coronary artery bypass graft and 6 cases (5.9%) died. A total of 170 coronary arteries were involved, including 24 (14.1%) GCAAs on the main trunk of left coronary artery, 10 (5.9%) GCAAs on left circumflex, 57 (33.5%) GCAAs on left anterior descending, 78 (45.9%) GCAAs on the middle segments of right coronary artery, and 1 (0.6%) GCAA in the distal segments of right coronary artery. Eleven cases (10.9%) recovered with the coronary artery absolute lumen diameter of all GCAAs below 4.0 mm. Among 170 branches with GCAAs, 28 (16.5%) regressed below 4.0 mm. No significant difference was found in the regression rates between right and left GCAA (18.7% (17/91) vs. 13.9% (11/79), χ²=2.473, P=0.116). There was no statistically significant difference in retraction between unilateral GCAA and bilateral GCAA (16.1% (9/56) vs. 4.4% (2/45), χ²=2.381, P=0.123). Conclusions: GCAA of KD occurred more common in the middle segments of right and left anterior descending coronary arteries. The incidence of adverse cardiac events and the mortality rate in children with GCAA complicated with KD was high. Their long-term prognosis was poor.

A functional modified graphene oxide/nanodiamond/nano zinc oxide composite for excellent vulcanization properties of natural rubber

A modified graphene oxide/nanodiamond/nanozinc oxide (MGO/ND/nanoZnO) functional hybrid filler is designed and prepared to improve the vulcanization efficiency of a rubber composite and to reduce the use of ZnO. ND was grafted onto graphite oxide with the aid of 4,4'-methylene diphenyl diisocyanate (MDI). NanoZnO, with high surface activity, was then loaded onto the MGO/ND complex through the wet chemical method, in order to synthesize the MGO/ND/nanoZnO functional hybrid filler. Rubber composites were prepared using the rubber latex composite method and their vulcanization behaviors were investigated. Our results show that the MGO/ND/nanoZnO functional hybrid filler can remarkably improve the vulcanization behaviors of the rubber composite. Compared with that of pure natural rubber (NR), the vulcanization activation energy of the rubber composite was reduced by approximately 16%. Moreover, the vulcanization efficiency can be improved by 63% (i.e., the optimum cure time is shortened from the original 405 s to 150 s) after the same amount of traditional ZnO was replaced by the functional hybrid filler loaded with 1 wt% nanoZnO. The prepared MGO/ND/nanoZnO functional hybrid filler thus provides a promising alternative to improve the vulcanization efficiency of rubber composites.

[Systematic review of the qualitative researches on care experience of caregivers of burn children]

Objective: To systematically review the care experience of caregivers of burn children, so as to provide references for guiding the continuing care in hospitals, communities, and homes. Methods: Databases including Cochrane Library, PubMed, ScienceDirect, ProQuest, Web of Science, and CINAHL were retrieved with the search terms of " burn" , " care/caregivers/nursing/father/mother/relatives" , " needs/perceptions/exceptions/attitudes/feelings/demands/experiences" , " qualitative research" , and the Chinese Journals Full-text Database, China Biology Medicine disc, VIP Database, and Wanfang Data were retrieved with the search terms in Chinese version of "//" , "//////" , "/////" , "" to search the qualitative researches on care experience of caregivers of burn children published from the establishment of the databases to November 2019. After screening and extracting the data, the quality evaluation criteria for qualitative research of the Australian Joanna Briggs Institute Evidence-Based Health Care Center and its integrative/aggregative synthesis method were used to assess the quality of the included literature and meta-integrate the research results respectively. Results: A total of 16 studies and 269 caregivers were enrolled. The quality of one included literature was grade A, and the quality of 15 included literature was grade B. A total of 65 research results were extracted with totally 6 categories formed after summarization, and 2 integrated results obtained as follows: (1) The caregivers experienced heavy psychological pressure and burden in the care process, which had a significant impact on family, social relations, and daily life. (2) With the care time lapsing, through the support of all sectors of society and self-adjustment, the caregivers gradually accepted the reality and actively took various countermeasures, but they still faced many challenges in disease care. Conclusions: The caregivers of burn children have many physical and mental health problems and face many care challenges. The government, medical and health institutions, and society should give a great attention to these issues, improve the social support system and security system, reduce the family-related pressure of burn children's families, and improve the quality of family life.

MiR-21 promotes fracture healing by activating the PI3K/Akt signaling pathway

OBJECTIVE

This study aims to elucidate the potential mechanism of micro ribonucleic acid (miR)-21 in promoting fracture healing.

MATERIALS AND METHODS

30 male Sprague-Dawley rats were randomly divided into group A (phosphate-buffered saline, PBS, n=10), group B (AntagomiR-21, n=10) and group C (AntagomiR-NC, n=10) according to the different treatments. The femoral fracture operation was performed in every rat, which was pathologically diagnosed via X-ray. After the successful modeling, 50 μL (2 nmoL) PBS, 50 μL AntagomiR-21 or 50 μL AntagomiR-NC was intraperitoneally injected into rats in group A, B or C, respectively. The above agents were injected once a week for 6 weeks. At 6 weeks, 3 rats were executed in each group, and the tissue at the fracture end was observed via hematoxylin-eosin (HE) staining. The fracture healing of rats was evaluated via imaging at 1 and 7 weeks. At the same time, the expression of miR-21 in the three groups was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR), and the expression of phosphatidylinositol 3-hydroxy kinase (PI3K) and phosphorylated-serine/threonine-protein kinase B (p-Akt) in the three groups was detected via Western blotting.

RESULTS

According to the histological staining, the bone repair at the fracture end of rats in group B was not significant with fracture and poor continuity compared with those in group A and group C. The imaging evaluation revealed that in group B, the callus tissues were significantly reduced, the fracture line had undesirable healing. There were no displacement and loosening of internal fixation compared with group A and group C. Besides, RT-PCR showed that the miR-21 expression declined markedly in group B compared with that in group A and group C, and the differences were statistically significant (p<0.05). Western blotting manifested that the protein levels of PI3K and p-Akt also declined in group B compared with those in group A and group C, and there were statistically significant differences (p<0.05).

CONCLUSIONS

MiR-21 promotes the fracture healing in fractured rats by activating the PI3K/Akt signaling pathway.

Air temperature, carbon dioxide, and ammonia assessment inside a commercial cage layer barn with manure-drying tunnels

Understanding the air temperature distribution, ammonia (NH₃) and carbon dioxide (CO₂) levels in poultry housing systems are crucial to poultry health, welfare, and productivity. In this study, 4 Intelligent Portable Monitoring Units and 7 temperature sensors were installed inside and between the cages and above 2 minimum ventilation fans of a commercial stacked-deck cage laying hen house in the Midwest United States (425,000 laying hens) to continuously monitor the interior environment over a 6-month period. During cold conditions (March 12th–May 22nd), there was a variation noted, with barn center temperatures consistently being highest in the longitudinal and lateral direction (P < 0.001) and the top floor deck warmer than the bottom floor (P < 0.05). During hotter conditions (May 23rd–July 26th), the interior thermal environment was more uniform than during the winter, resulting in a difference only in the longitudinal direction. The daily CO₂ and NH₃ concentrations were 400 to 4,981 ppm and 0 to 42.3 ppm among the 4 sampling locations, respectively. Both CO₂ and NH₃ decreased linearly with increasing outside temperatures. The mean NH₃ and CO₂ concentrations varied with sampling locations and with the outside temperatures (P < 0.001). For CO₂, the minimum ventilation sidewall had lower values than those measured in the barn’s center (P < 0.05) during cold weather, while the barn center and the manure room sidewall consistently measured the highest concentrations during warmer weather (P < 0.05). For NH₃, the tunnel ventilation inlet end consistently had the lowest daily concentrations, whereas the in-cage and manure drying tunnel sidewall locations measured the highest concentrations (P < 0.001). Higher NH₃ and CO₂ concentrations were recorded within the cage than in the cage aisle (P < 0.05). The highest NH₃ concentration of 42 ppm was recorded above the minimum exhaust fan adjacent to the manure drying tunnel, which indicated that higher pressure (back pressure) in the manure drying tunnel allowed air leakage back into the production area through nonoperating sidewall fan shutters.