[Prevalence and trend analysis of severe multiple disabling birth defects in Chongqing City from 2007 to 2020].

Objective: To explore the prevalence and change trend of severe multiple disabling birth defects in Chongqing City from 2007 to 2020, and to provide a basis for comprehensive prevention and control measures of severe multiple disabling birth defects. Methods: Based on hospital monitoring data, 1 103 children with severe multiple disabling birth defects monitored by all birth defects monitoring institutions in Chongqing City from January 2007 to December 2020 were included in the study. They were grouped by year, perinatal gender, maternal permanent residence (urban/rural), maternal age, different regions and other categories. Chi-square test was used to analyze the differences in the incidence of severe multiple disabling birth defects in different categories, and linear trend test was used to analyze the change trend. Results: From 2007 to 2020, a total of 1 022 314 perinatal births and 1 103 severe multiple disabling birth defects were monitored in Chongqing City, with an incidence of 10.79/10 000, including 11.47/10 000 in urban areas and 9.48/10 000 in rural areas, with an incidence higher in urban areas than in rural areas(χ2=8.424,P=0.004). Male was 10.47/10 000, female was 10.97/10 000, there was no significant difference between male and female(χ2=0.606,P=0.436). The incidence of maternal in different age groups was u-shaped, and there was statistical difference in incidence among different age groups (χ2=59.465, P<0.001). The incidence of maternal in<20 years old and ≥35 years old was higher, and in 25-29 years old was lower. The incidence rate was 17.96/10 000 in 2007 and 7.18/10 000 in 2020, which decreased by 60.02% in 2007-2020. The incidence of neural tube defect, chromosome syndrome, limb shortening and abdominal wall defect decreased by 78.12%, 77.38%, 80.55% and 91.30%, respectively. Severe Congenital heart disease rose by 456.16%. From 2007 to 2020, the overall incidence of the disease showed a decreasing trend (χ2trend =117.046, P<0.001), except for the rise of severe congenital heart disease, (χ2trend=8.744, P=0.003), the other four types of diseases were on the decline (neural tube defects χ2trend =48.618, P<0.001; chromosome syndrome χ2trend=50.999, P<0.001; limb shortening χ2trend=73.464, P<0.001; abdominal wall defect χ2trend=79.863, P<0.001). Conclusion: From 2007 to 2020, the incidence of severe disabling birth defects in Chongqing City showed a downward trend, and there were regional and age differences. The incidence of severe congenital heart disease is on the rise.

[Schwannoma originating from the branch of the inferior oblique muscle innervated by the oculomotor nerve: a report of two cases].

Patient 1 was a 44-year-old female with a progressively enlarging orbital mass on the right side for 2 years, while patient 2 was a 25-year-old female who complained of protrusion of the right eye for 2 months. Both patients presented with exophthalmos and a palpable infraorbital mass without vision loss. Magnetic resonance imaging examination showed a well circumscribed circular orbital lesion, with hypointensity on T1 weighted image and heterogeneous hyperintensity on T2 weighted image, which could be significantly enhanced, in either eye. Both eyes were diagnosed as begin orbital tumor and received resection under general anesthesia. Intraoperatively, the distal end of the tumors was found to transmigrate to normal nerves and insert into the inferior oblique muscle. Combined with the pathological diagnosis of schwannoma and postoperative occurrence of mydriasis and inferior oblique muscle paralysis in both patients, it was confirmed that the two lesions were schwannomas originating from the branch of the inferior oblique muscle innervated by the oculomotor nerve.

[Comparative study on metagenomics of esophageal flora in elderly and middle-aged esophageal squamous cell carcinoma patients].

Objective: To explore the flora characteristics and differences of esophageal tissues between elderly esophageal squamous cell carcinoma (ESCC) patients and young and middle-aged ESCC patients, so as to assist in studying the potential biomarkers of elderly ESCC patients. Methods: In this study, a retrospective study was adopted. 72 ESCC patients diagnosed in Taihe Hospital, Shiyan City, Hubei Province from July 2018 to July 2019 were selected, including 49 patients in the elderly group (≥ 60 years old, 40 males and 9 females), 23 patients in the young and middle-aged group (<60 years old, 21 males and 2 females). In the same period, 20 healthy persons without abnormal gastroscopy in endoscopy center were selected as the control group (aged 35-78 years old, median age 57 years old, 16 males and 4 females). The genomic DNA was extracted from the affected esophageal tissues of patients with ESCC and the middle esophageal samples of the control group. The V4 hypervariable region of bacterial 16SrRNA gene sequence was amplified. Illumina HiSeq sequencing technology was adopted. The flora characteristics of elderly, young and middle-aged ESCC patients was compared and analyzed. QIIME and Rstudio software were used to analyze the sequence data, and nonparametric Kruskal-Wallis test or Wilcoxon rank sum test were used for statistical methods. Results: Shannon index [5.17 (4.53, 5.95) vs. 4.79 (3.74, 5.97)], Simpson index [0.94 (0.91, 0.96) vs. 0.92 (0.83, 0.96)] and Chao1 index [343.55 (259.76, 570.59) vs. 329.16 (268.88, 648.00)] were similar in flora of two groups, and there was no significant difference (Z=-0.791, -1.057, -0.380, all P>0.05). There was no significant difference in ß-diversity between the elderly group and the young and middle-aged group (PC1=19.14%, PC2=6.95%, PPC1=0.67, PPC2=0.42). At the phyla level, the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria in the young and middle-aged group, while the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria and Actinobacteria in the elderly group; the significant difference between the two groups was Fusobacteria (Q=0.596, P<0.05). At the genus level, the top 5 genera in the young and middle-aged group in abundance were as follows: Prevotella, Bacteroides, Streptococcus, Selenomonas and Veillonella. In the elderly group, Prevotella, Bacteroides, Streptococcus, Selenomonas and Haemophilus were the top 5 in abundance, and there were significant difference in Fusobacterium between the two groups (Q=0.938, P<0.05). PICRUSt function prediction showed that the abundance of Aminoacyl.tRNA.biosynthesis, Nucleotide.excision.repair, RNA.polymerase, Ribosome, Clavulanic.acid.biosynthesis, Photosynthesis and Photosynthesis. proteins in the elderly group were lower than those in the young and middle-aged group (all Q=0.734, P<0.05). Conclusion: There is no significant difference in α-diversity and ß-diversity between elderly ESCC patients and young and middle-aged patients, but the abundance of Fusobacterium flora increased.

[The imaging signs and significances of the enlargement of the infraorbital nerve and the frontal nerve in orbital lymphoproliferative diseases].

Objective: To describe imaging signs of infraorbital nerve enlargement (IONE) and frontal nerve enlargement (FNE) in orbital lymphoproliferative diseases (LPDs), and to explore the diagnostic value and differential diagnostic role of the signs. Methods: A retrospective case series study. The data of 222 cases (262 eyes) of LPDs and 95 cases (134 eyes) of inflammatory pseudotumors (IPs) pathologically confirmed by the Peking University People's Hospital and the Third Medical Center of the Chinese PLA General Hospital from January 2013 to December 2018 were analyzed. The LPDs were lymphoma (including atypical lymphoid hyperplasia) in 91 cases (110 eyes) and reactive lymphoid hyperplasia (RLH) in 131 cases (152 eyes). The patients with LPD included 101 males and 121 females, aged (58±17) years, and the patients with IP included 44 males and 51 females, aged (49±21) years. All patients underwent orbital CT or MRI with T1 weighted imaging, T2 weighted imaging and enhanced T1 weighted imaging scanning. Slice thickness was 3 mm. In the coronal CT or MRI, the criterion for determining IONE was the inferior orbital nerve diameter greater than the optic nerve, and the criterion for determining FNE was the forehead nerve diameter equal to or greater than the optic nerve. The pathological types and imaging features of nerve enlargement were recorded. The incidence rates of different pathological types were compared using chi-square test. Results: The enlarged nerves showed homogeneous soft tissue density on CT images, accompanied with enlarged bony infraorbital nerve grooves (foramina). MRI showed moderate signals of T1 and T2 weighted imaging, with clear boundaries and obvious enhancement, which could spread to the pterygopalatine fossa and the cranial cavity. The accompanying images included the enlargement of lacrimal glands or extraocular muscles, intraorbital mass or sinuses opacity. The IONE and/or FNE were found in 12 patients with LPD, but were not found in any patients with IP. The difference was statistically significant (12/222 vs. 0/95, χ²=5.337, P=0.021). Among the cases with nerve enlargement, there were 2 cases of diffuse large B cell lymphoma and 10 cases of RLH (2/91 vs. 10/131, χ²=3.103, P=0.078), as well as 7 cases of IgG4-related ophthalmic disease (IgG4-ROD) and 3 cases of non-IgG4-ROD (7/28 vs. 3/103, χ2=15.232, P=0.000). Conclusions: Lymphoma and RLH can express IONE and/or FNE, in which the IgG4-ROD is the most common and specific type. CT and MRI scans can show enlarged nerves and accompanying signs. Neural thickening can also be applied as a discrimination marker of LPDs and IPs. (Chin J Ophthalmol, 2020, 56: 832-838).

Depth of field extension and objective space depth measurement based on wavefront imaging.

When all the parts of the wavefront imaging system are kept static after wavefront measuring, the target's images are blurry, because the depth of field (DOF) of the system affects the imaging quality. In this paper, the method for extending the DOF of the wavefront imaging system through an integrated architecture of a liquid-crystal microlens array (LCMLA) powered by electricity and a common photosensitive array, is presented. The DOF can be extended remarkably only by stitching together several sub-images of the LCMLA. The problem that the wavefronts and imaging results are insensitive to the objective depth is also solved. Optimal driving voltage signals are found out according to Sobel mean gradient to efficiently calibrate the depth of objective space in order to quantitatively measure the depth. The approach indicates a viable way to effectively extend the DOF of imaging micro-systems and to measure the geometrical depth of targets at the same time.

Extraction of DNA from Sperm Cells in Mixed Stain by Nylon Membrane Bushing Separation Technique.

OBJECTIVES: To establish a novel method for the separation of sperm cells in mixed stain, and to evaluate its application value. METHODS: Totally 40 mixed stain samples were collected from sexual assault cases. Sperm cells were separated by the conventional differential lysis method and the nylon membrane bushing separation technique, respectively. The DNA of sperm cells was extracted with the silicon membrane kit （Forensic DNA Extraction Kit for Soft Tissues）. The PCR amplification was performed using AmpFℓSTR® Identifiler® Plus kit, and the products were electrophoresed by 3500xL genetic analyser. The results of two separation methods were then compared. RESULTS: Complete and single-source male STR genotypes could be obtained from all the 40 mixed stain samples except three samples with minimal residual of female DNA by the nylon membrane bushing separation technique. The STR genotypes of sperm cells could not be detected in 25 samples, which were obtained in 15 samples （seven were of incomplete male STR genotypes, six with residual of female DNA, two were complete and single-source STR genotypes of sperm cells）. CONCLUSIONS: The nylon membrane bushing separation technique developed in present study can be used in the separation of sperm cells in mixed stain, especially for the extraction of a small amount of sperm from a large quantity of female cells, which is inexpensive, rapid and simple.

Behavior of tetracycline and sulfamethoxazole and their corresponding resistance genes in three-dimensional biofilm-electrode reactors with low current.

Antibiotics and antibiotic resistance genes (ARGs) have become major health concerns. In this study, three-dimensional biofilm-electrode reactors (3D-BERs) under low current were designed to assess their performance in removing tetracycline (TC) and sulfamethoxazole (SMX) from synthetic wastewater. In addition, the fates of the corresponding ARGs in microbial communities were investigated. The mass removal ratios of TC and SMX by the 3D-BERs were 82.6-97.3% and 72.2-93.2%, respectively. There were obvious increases in the relative abundances of all target genes after ∼2 months. The tet and sul genes were significantly upregulated by high concentrations of antibiotics in the cathode layer, and higher ARG levels were evident in the cathodes than in the anodes. High-throughput sequencing identified Methylotenera, Candidatus Accumulibacter, Limnohabitans, Dechloromonas, Crenothrix, and Caldilinea as the dominant genera in the samples at the end of the experiment, after ∼8 months, and these bacteria potentially exhibited antibiotic resistance. The relative abundances and compositions of the dominant microbial populations changed throughout the course of antibiotic removal in the 3D-BERs.

[Application of lymph node labeling with carbon nanoparticles by preoperative endoscopic subserosal injection in laparoscopic radical gastrectomy].

Objective: To evaluate the application value of carbon lymph node tracing technique by preoperative endoscopic subserosal injection in laparoscopic radical gastrectomy. Methods: From June 2013 to February 2015, seventy eight patients with gastric cancer were enrolled and randomly divided into trial group and control group. Subserosal injection of carbon nanoparticles around the tumor was performed by preoperative endoscopic subserosal injection one day before the operation in trial group, while the patients routinely underwent laparoscopic gastrectomy in control group. Results of harvested lymph nodes, postoperative complications were compared between the two groups. Carbon nanoparticle-related side effect was also evaluated. Results: The average number of harvested lymph node in trial group was significantly higher than that in control group (35.5±8.5 vs 29.5±6.5, P<0.05). The rate of overall black-dyed harvested lymph node was 74.7% (1 035/1 386) in trial group, the black-dyed lymph node rate in D1 lymph node was 80.1%, which was significantly higher than that in D2 lymph node (69.8%, χ2=19.38, P<0.01). When comparing the lymph node with and without black-dyed in trial group, the rate of metastasis lymph node was significantly higher in lymph node with black-dyed (17.3% vs 4.0%, χ2=38.67, P<0.01). There was no significant difference in postoperative complications rate between two group (trial group 10.2%; control group 12.8%, χ2=0.00, P>0.05), and no carbon nanoparticle-related side effect was observed. Conclusion: Given a higher harvested lymph node number and a similar rate of complications, preoperative endoscopic subserosal injection of carbon nanoparticles was safe and feasible.

[Value of the albumin to globulin ratio in predicting severity and prognosis in myasthenia gravis patients].

OBJECTIVE: To assess the predictive value of the albumin to globulin ratio (AGR) in evaluation of disease severity and prognosis in myasthenia gravis patients. METHODS: A total of 135 myasthenia gravis (MG) patients were enrolled between February 2009 and March 2015. The AGR was detected on the first day of hospitalization and ranked from lowest to highest, and the patients were divided into three equal tertiles according to the AGR values, which were T1 (AGR <1.34), T2 (1.34≤AGR≤1.53) and T3 (AGR>1.53). The Kaplan-Meier curve was used to evaluate the prognostic value of AGR. Cox model analysis was used to evaluate the relevant factors. Multivariate Logistic regression analysis was used to find the predictors of myasthenia crisis during hospitalization. RESULTS: The median length of hospital stay for each tertile was: for the T1 21 days (15-35.5), T2 18 days (14-27.5), and T3 16 days (12-22.5) (P<0.01), and Kaplan-Meier curves showed significant difference among the three groups. In the univariate model, serum albumin, creatinine, AGR and MGFA clinical classification were related to prognosis of myasthenia gravis. At the multivariate Cox regression analysis, the AGR (P<0.001) and MGFA clinical classification (P<0.001) were independent predictive factors of disease severity and prognosis in myasthenia gravis patients. Respectively, the hazard ratio (HR) were 4.655 (95% CI: 2.355-9.202) and 0.596 (95% CI: 0.492-0.723). Multivariate Logistic regression analysis showed the AGR (P<0.001) and MGFA clinical classification were related to myasthenia crisis. CONCLUSION: The AGR may represent a simple, potentially useful predictive biomarker for evaluating the disease severity and prognosis of patients with myasthenia gravis.

[Research advances in the role of CX3CL1 and its receptor in liver diseases].

In recent years, an increasing number of studies have found that the interaction between CX3CL1 and its receptor plays an important role in a series of inflammatory, infectious, and neurological processes and in various cancers. Therefore, its therapeutic targeting represents a promising treatment strategy for diseases. This review summarizes the structure, biological function, and mechanism of signal transduction of CX3CL1 and its receptor, and introduces the research progress in CX3CL1 and its receptor in hepatitis, hepatic fibrosis, cirrhosis, and hepatoma.

[Protective effect and mechanism of ischemic postconditioning in rats underwent myocardial ischemia/ reperfusion injury].

OBJECTIVE: This study is designed to observe the effect of ischemic postconditioning in rats underwent acute myocardial ischemia/reperfusion injury and to investigate the related mechanism. METHODS: A total of 30 SD rats were randomly divided into sham operation group (control group, n=10), ischemia/reperfusion group (IR group, n=10) and ischemic postconditioning group (PC group, n=10) based on random number table. Rats in IR group underwent 30 minutes myocardial ischemia by occlusion of the proximal portion of left anterior descending (LAD) coronary artery followed by 2 hours reperfusion. In control group, there was no IR intervention. In PC group, at the start of reperfusion, three cycles of 30 seconds reperfusion and 30 seconds LAD reocclusion preceded the 2 hours of reperfusion. The hemodynamic values were measured via a cannula inserted into the right common carotid artery.The area at risk was assessed by Evans blue staining and the infarct size as measured by TTC staining.Western blot and Real time PCR were respectively used to assess the expression of predicted target gene Bim and microRNA-214(miR-214) in the area at risk at the end of 2 hours reperfusion. RESULTS: (1) The hemodynamic monitoring in different groups: the left ventricular systolic pressure (LVSP), ±dp/dtmax, and heart rate of IR group and PC group were lower than those of control group, but left ventricular end-diastolic pressure (LVEDP) was higher than that of control group (all P<0.05). The LVSP and ±dp/dtmax of PC group were higher than those of IR group, and LVEDP was lower than that of IR group (all P<0.05). (2) Myocardial ischemia area and infarction range in different groups: there was no statistically difference in the proportion of area at risk (AAR) in left ventricle (LV) (AAR/LV) between PC group and IP group ((27.00 + 7.55) % vs. (26.67 + 11.68) %, P>0.05). The proportion of infarct size in the area at risk(IS/AAR) of PC group was lower than that of IR group((30.67±3.51)% vs. (48.67±4.62)%, P<0.05). (3) The expression of Bim protein in rats ischemic myocardial tissue in different groups: the expression of Bim protein in ischemic myocardial tissue of IR group was higher than that of control group (2.34±0.15 vs. 0.75±0.05, P<0.05), and that of PC group was lower than IR group (1.25±0.14 vs. 2.34±0.15, P<0.05). (4) The expression of of miR-214 in rats ischemic myocardial tissue in different groups: the expression of miR-214 of IR group was lower than that of control group(0.20±0.04 vs. 1.00, P<0.01), and that of PC group was higer than that of IR group (0.85±0.20 vs. 0.20±0.04, P<0.01). There was no statistically difference between PC group and control group (P>0.05). CONCLUSIONS: Postconditioning could significantly decrease the ischemia/reperfusion injury by reducing the infarct size and improve cardiac function in this in vivo rat model. The expression of Bim in postconditioning group is significantly depressed, which may play an important role in the protection process of postconditioning, and the downregulation of Bim might be mediated with the increase of miR-214 expression.

Suppression of Inflammatory Responses by Dihydromyricetin, a Flavonoid from Ampelopsis grossedentata, via Inhibiting the Activation of NF-κB and MAPK Signaling Pathways.

Ampelopsis grossedentata, an indigenous plant in southern China, has been used for treating pharyngitis in traditional Chinese medicine for hundreds of years. In this study, we explored the anti-inflammatory activity of dihydromyricetin (1), its major bioactive component, and the underlying mechanism of this action. We demonstrated that 1 suppressed the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) as well as increased the level of the anti-inflammatory cytokine interleukin-10 (IL-10) in lipopolysaccharide (LPS)-treated mice. Moreover, 1 was found to markedly inhibit the production of nitric oxide (NO) and the levels of TNF-α, IL-1ß, and IL-6, whereas it increased the level of IL-10 in LPS-induced RAW 264.7 macrophage cells. Compound 1 also reduced the protein expression of inducible nitric oxide synthase (iNOS), TNF-α, and cyclooxygenase-2 (COX-2) in macrophage cells. Furthermore, 1 suppressed the phosphorylation of NF-kappa B (NF-κB) and IκBα as well as the phosphorylation of p38 and JNK but not ERK1/2 in LPS-stimulated macrophages. Taken together, the present results suggest that 1 exerts its topical anti-inflammatory action through suppressing the activation of NF-κB and the phosphorylation of p38 and JNK. Thus, 1 may be a potentially useful therapeutic agent for inflammatory-related diseases.

An insight into the heat and mass transfer mechanisms of eggshells hatching broiler chicks and its effects to the hatcher environment.

Thermodynamic study of incubated eggs is an important component in the optimisation of incubation processes. However, research on the interaction of heat and moisture transfer mechanisms in eggs is rather limited and does not focus on the hatching stage of incubation. During hatch, both the recently hatched chick and the broken eggshell add extra heat and moisture contents to the hatcher environment. In this study, we have proposed a novel way to estimate thermodynamically the amount of water evaporated from a broken eggshell during hatch. The hypothesis of this study considers that previously reported drops in eggshell temperature during hatching of chicks is the result remaining water content evaporating from the eggshell, released on the inner membrane by the recently hatched wet chick, just before hatch. To reproduce this process, water was sprayed on eggshells to mimic the water-fluid from the wet body of a chick. For each sample of eggshell, the shell geometry and weight, surface area and eggshell temperature were measured. Water evaporation losses and convection coefficient were calculated using a novel model approach considering the simultaneous heat and mass transfer profiles in an eggshell. The calculated average convective coefficient was 23.9 ± 7.5 W/m(2) °C, similar to previously reported coefficients in literature as a function of 0.5-1m/s air speed range. Comparison between measured and calculated values for the water evaporation showed 68% probability accuracy, associated to the use of an experimentally derived single heat transfer coefficient. The results support our proposed modelling approach of heat and mass transfer mechanisms. Furthermore, by estimating the amount of evaporated water in an eggshell post-hatch, air humidity levels inside the hatcher can be optimised to ensure wet chicks dry properly while not dehydrating early hatching chicks.

Higher levels of CO2 during late incubation alter the hatch time of chicken embryos.

1. It has been reported that the increasing CO2 tension triggers the embryo to pip the air cell and emerge from the egg. However, the mechanism by which higher CO2 concentrations during the last few days of incubation affect chick physiology and the hatching process is unclear. This study investigated the effect of CO2 concentrations up to 1% during pipping, on the onset and length of the hatch window (HW) and chick quality. 2. Four batches of Ross 308 broiler eggs (600 eggs per batch) were incubated in two small-scale custom-built incubators (Petersime NV). During the final 3 d of incubation, control eggs were exposed to a lower CO2 concentration (0.3%), while the test eggs experienced a higher CO2 concentration programme (peak of 1%). 3. There were no significant differences in blood values, organ weight and body weight. There was also no difference in hatchability between control and test groups. However, a small increase in the chick weight and the percentage of first class chicks was found in the test groups. Furthermore, plasma corticosterone profiles during hatching were altered in embryos exposed to higher CO2; however, they dropped to normal levels at d 21 of incubation. Importantly, the hatching process was delayed and synchronised in the test group, resulting in a narrowed HW which was 2.7 h shorter and 5.3 h later than the control group. 4. These results showed that exposing chicks to 1% CO2 concentration during pipping did not have negative impacts on physiological status of newly hatched chicks. In addition, it may have a significant impact on the physiological mechanisms controlling hatching and have benefits for the health and welfare of chickens by reducing the waiting time after hatching.

Effect of species-specific sound stimulation on the development and hatching of broiler chicks.

1. Previous research has reported that chicken embryos develop a functionary auditory system during incubation and that prenatal sound may play an important role in embryo development and alter the hatch time. In this study the effects of prenatal auditory stimulation on hatch process, hatch performance, the development of embryo and blood parameters were investigated. 2. Four batches of Ross 308 broiler breeder eggs were incubated either in control or in sound-stimulated groups. The sound-stimulated embryos were exposed to a discontinuous sound of species-specific calls by means of a speaker at 72 dB for 16 h a day: maternal calls from d 10 to d 19 of incubation time and embryo/chick calls from d 19 until hatching. The species-specific sound was excluded from the control group. 3. The onset of hatch was delayed in the sound-stimulated group compared to the controls. This was also supported by comparison of the exact hatching time of individual focal chicks within the two groups. However, the sound-stimulated embryos had a lower hatchability than the control group, mainly due to significantly increased numbers of late deaths. 4. The embryos exhibited a similar growth pattern between the sound-stimulated group and the control group. Although sound exposure decreased body weight at d 16, no consistent effect of sound on body weight at incubation stage was observed. Species-specific sound stimulation also had no impact on chick quality, blood values and plasma corticosterone concentrations during hatch.

Spatial distribution, movement, body damage, and feather condition of laying hens in a multi-tier system.

The welfare and health of laying hens in the multitier system raise concern in public. The flock distributions during feeding time at 51 and 89 wk were studied in a multitier system. Furthermore, the ultra-high frequency radio frequency identification (UHF RFID) equipment was used to identify the transition between tiers and time spent in each tier of 48 focal hens (12 hens from each tier-group of the multitier system) at 92 wk of age. The body weight, tibia size (length and width), body damage (comb and rear part), and feather condition (neck, breast, back, tail, cloaca, and wings) of focal hens from different tier-groups were further compared. The results showed that the spatial distribution in flocks changed from top to bottom with increasing age. The hens at 51 wk of age were mainly distributed in the 4th tier (19.6 ± 5.0% in 1st tier, 9.6 ± 1.1% in 2nd tier, 23.6 ± 2.9% in 3rd tier and 47.3 ± 2.6% in 4th tier), and hens at 89 wk of age were mainly distributed in the lower tiers (33.5 ± 1.5% in 1st tier, 31.9 ± 5.1% in 2nd tier, 15.7 ± 3.4% in 3rd tier and 16.6 ± 3.1% in 4th tier). The spatial distribution of hens at 89 wk of age was more even than that at 51 wk of age. At 92 wk of age, the proportion of time spent in original tier of 4 tier-groups was 91.0 ± 5.7%, 51.9 ± 5.7%, 59.0 ± 7.0% and 63.0 ± 6.7%, respectively. Focal hens preferred to stay in the original tier and spent significantly less time in other tiers (P < 0.05). There was no significant difference in body weight, body damage score, tibia width and partial feather scores (neck, breast, tail, and cloaca) of focal hens among 4 tier-groups (P > 0.05). However, focal hens from 1st tier had worse feather scores on wings and back, and shorter tibia length compared to other tiers suggesting that there were more lower ranking birds that located in lower tier to avoid competition, but had equal access to resource, which is good for their welfare and health. In summary, the overcrowding situation was improved near the end of the laying cycle in the multitier system, thereby mitigating the potential negative effects to the lower ranking hens and maintain a satisfactory level of welfare and health for laying hens near the end of the laying cycle.

Embryonic development and the physiological factors that coordinate hatching in domestic chickens.

Embryonic growth and development is influenced by both endogenous and exogenous factors. The purpose of this review is to discuss the critical stages of chick embryonic development in relation to functional maturation of numerous organ systems, the acquisition of thermoregulation, and the hatching process. In addition, the mechanism of hatching, including sound synchronization and hormonal and environmental stimulation, will be discussed. Finally, the importance of effective hatching synchronization mechanisms will also be highlighted.