[Research on the establishment of standard limits for perfluorooctanoic acid and perfluorooctane sulfonate in the "Standards for Drinking Water Quality（GB5749-2022）"in China].

Perfluorinated compounds, especially Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), are widely detected in water environments in China. Considering the potential health risks of drinking water exposure routes, PFOA and PFOS have been added to the water quality reference index of the newly issued "Standards for Drinking Water Quality (GB5749-2022)", with limit values of 40 and 80 ng/L, respectively. This study analyzed and discussed the relevant technical contents for determining the limits of the hygiene standard, including the environmental existence level and exposure status of PFOA and PFOS, health effects, derivation of safety reference values, and determination of hygiene standard limits. It also proposed prospects for the future direction of formulating drinking water standards.

[Diagnostic value of novel hepatic fibrosis markers in assessing cirrhosis in patients with chronic hepatitis C].

Objective: To investigate the efficacy of chitinase-3-like protein 1 (CHI3L1) and Golgi protein 73 (GP73) in the diagnosis of cirrhosis and the dynamic changes of CHI3L1 and GP73 after HCV clearance in patients with chronic hepatitis C (CHC) treated with direct-acting antiviral drugs (DAAs). The comparison of continuous variables of normal distribution were statistically analyzed by ANOVA and t-test. The comparison of continuous variables of non-normal distribution were statistically analyzed by rank sum test. The categorical variables were statistically analyzed by Fisher's exact test and χ(2) test. Correlation analysis was performed using Spearman correlation analysis. Methods: Data of 105 patients with CHC diagnosed from January 2017 to December 2019 were collected. The receiver operating characteristic curve (ROC curve) was plotted to study the efficacy of serum CHI3L1 and GP73 for the diagnosis of cirrhosis. Friedman test was used to compare CHI3L1 and GP73 change characteristics. Results: The areas under the ROC curve for CHI3L1 and GP73 in the diagnosis of cirrhosis at baseline were 0.939 and 0.839, respectively. Serum levels of CHI3L1 and GP73 in the DAAs group decreased significantly at the end of treatment compared with baseline [123.79 (60.25, 178.80) ng/ml vs. 118.20 (47.68, 151.36) ng/ml, P = 0.001; 105.73 (85.05, 130.69) ng/ml vs. 95.52 (69.52, 118.97) ng/ml, P = 0.001]. Serum CHI3L1 and GP73 in the pegylated interferon combined with ribavirin (PR) group were significantly lower at the end of 24 weeks of treatment than the baseline [89.15 (39.15, 149.74) ng/ml vs. 69.98 (20.52, 71.96) ng/ml, P < 0.05; 85.07 (60.07, 121) ng/ml vs. 54.17 (29.17, 78.65) ng/ml, P < 0.05]. Conclusion: CHI3L1 and GP73 are sensitive serological markers that can be used to monitor the fibrosis prognosis in CHC patients during treatment and after obtaining a sustained virological response. Serum CHI3L1 and GP73 levels in the DAAs group decreased earlier than those in the PR group, and the serum CHI3L1 levels in the untreated group increased compared with the baseline at about two years of follow-up.

[Preliminary application of the Asia-Pacific colorectal screening score combined with the quantitative fecal occult blood in colorectal neoplasia screening].

To evaluate the efficacy of the Asia-Pacific colorectal screening (APCS) score combined with the quantitative fecal immunochemical test in colorectal neoplasia screening. Subjects who appointment to receive colonoscopy were recruited from August 2017 to May 2019 in the digestive endoscopy center. Before the colonoscopy, all subjects were scored by the Asia Pacific colorectal cancer screening scoring system and measured by quantitative fecal immunochemical test (QFIT). The detection rates of colorectal neoplasia were compared to evaluate the efficacy of the combined assay in colorectal neoplasia screening between APCS score and QFIT. A total of 1 420 subjects were enrolled in this study, APCS score medium-risk (MR) and high-risk (HR) groups were 847 (59.7%) and 573 (40.4%) and 26 cases (1.8%) of colorectal cancer, 196 cases (13.8%) of advanced adenoma, and 395 cases (27.8%) of non-advanced adenoma were detected. With the combination of APCS score and QFIT, participants were classified into 4 groups high-risk with positive QFIT result group G1, high-risk with negative QFIT result group G2, medium-risk with positive QFIT group G3, medium-risk negative QFIT group G4. The prevalence of colorectal neoplasia was 64.3%, 16.4%, 55.0%, and 9.8%, respectively. The prevalence of advanced neoplasia in high-risk with QFIT results was significantly higher than that in other 3 groups. HR and positive QFIT were the indicators for further colonoscopy, and MR with FIT negative group could postpone colonoscopy and conduct annual QFIT follow-up. The combination of APCS score and QFIT for colorectal neoplasia screening can reduce unnecessary colonoscopy, improve colonoscopy compliance and screening efficiency, and has important clinical significance and promotion value in colorectal tumor screening.

[Analysis of diagnosis and treatment of 100 patients with Hürthle cell adenoma].

OBJECTIVE: To summarize and analyze the clinical data and prognosis of the patients with Hürthle cell tumor (HCT) in order to raise the clinicians' awareness of the disease. METHODS: The clinical data on patients with histopathologically proven HCT, without other thyroid carcinomas, were collected retrospectively in Peking University First Hospital from January 2001 to February 2017. All the patients underwent surgery due to thyroid nodules. The follow-up information was also collected. RESULTS: A total of 100 patients were enrolled in the current study. All of them were diagnosed with Hürthle cell adenoma (HCA). There were 77 females and 23 males, with the male-to-female ratio of 1 : 3.3. The average age of these patients was (52±14) years at the time of operation. Fifty-one patients were found their thyroid nodules accidentally by ultrasonography during their health check-ups. 69.4% of the 49 symptomatic patients presented with painless cervical nodules. 83.0% HCA patients were combined with multinodular goiters (MNGs). 88.4% (76/86) patients were euthyroid and 53.8% (21/39) had increasing thyroglobulin levels. The mean longest diameter of HCAs was (3.2±1.5) cm (range: 0.9-7.3 cm) on ultrasonography. There were a series of sonographic features of HCA, such as larger, solidity, hypoecho, a smooth outline, intranodular vascularization, perinodular vascularization, absence of calcification in nodules and absence of enlarged cervical lymph nodes. Compared with the histological diagnosis, the diagnostic accuracy by frozen section (FS) during operation was 97.4%. Twenty-nine patients were followed up with an average period of (49.2±22.1) months and none of them had local recurrence or cervical lymph node metastasis. Six patients accepted thyroid hormone replacement treatment and one had thyrotoxicosis due to over-dose. CONCLUSION: HCA is more common in women. It is often found accidentally by ultrasonography during their health check-ups or presented with painless cervical nodules. It is combined with MNG frequently. HCA exhibits numerous sonographic features but not unique. FS during operation is a reliable method to identify HCA with high diagnostic accuracy. Patients with thyroid hormone administration should be monitored for thyroid function after thyroid surgery.

[The optimal thresholds of the quantitative fecal immunochemical test for opportunistic screening of colorectal neoplasia].

Objective: To investigate the significance of quantitative fecal immunochemical test (FIT) for opportunistic screening of colorectal neoplasia, and to propose the most optimal thresholds to improve the screening level of early colorectal neoplasia. Methods: The opportunistic screening participants were recruited from the Department of Gastroenterology & GI Endoscopy Center of the Seventh Medical Center of PLA General Hospital, and stool sample was collected before colonoscopy and the quantitative FIT was analyzed by OC-MICRO analysator for each patient. We assessed test performance in detecting colorectal neoplasia (advanced adenoma and CRC)with different thresholds on sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: A total of 1 448 objects were enrolled in this study, including 714 male (49.3%)and 734 female (50.7%).All participants were classified according to the result of colonoscopy and pathology, and 242 cases of colorectal neoplasia were found, containing 157 advanced adnoma and 85 colorectal cancer. The FIT threshold increased from 50 µg/L to 200 µg/L, while the positivity rate dropped from 11.5% to 8.6% and the sensitivity in detecting colorectal neoplasia dropped from 47.9% to 38.8%. However, the specificity increased from 96.8% to 98.2% and the positive predictive value increased from 82.3% to 87.0%.The miss rate of colorectal cancer increased from 11.8% (n=10) to 17.6% (n=15) along with the increase in FIT thresholds, but the miss rate of 100 µg/L and 150 µg/L was the same as 12.9% (n=11). Conclusions: Quantitative FIT,which is simple and fast,with the threshold of 100 µg/L for opportunistic screening, has a high sensitivity and specificity for the diagnosis of colorectal neoplasia,and is an important index in screening and diagnosis of colorectal neoplasia.

Raman-shifted wavelength-selectable pulsed fiber laser with high repetition rate and high pulse energy in the visible.

A high-pulse-energy, diffraction-limited, wavelength-selectable, visible source, based on Raman frequency shifting of a frequency-doubled Yb-doped fiber laser, has been studied. The relative length-scaling laws of Raman gain and self-phase modulation push the design towards short fiber lengths with large core size. It is experimentally demonstrated that the Raman clean-up effect in a graded-index multi-mode fiber is not sufficient to obtain diffraction-limited beam quality in the short fiber length. Thus, a large-core photonic crystal fiber is used to maintain diffraction-limited performance and output pulse energies of ~1 µJ, at a 1-MHz repetition rate and 1.3-ns pulse-width are successfully achieved. This step-tunable visible source should find applications in photoacoustic microscopy.

Lattice Boltzmann modeling of self-propelled Leidenfrost droplets on ratchet surfaces.

In this paper, the self-propelled motion of Leidenfrost droplets on ratchet surfaces is numerically investigated using a thermal multiphase lattice Boltzmann model with liquid-vapor phase change. The capability of the model for simulating evaporation is validated via the D(2) law. Using the model, we first study the performances of Leidenfrost droplets on horizontal ratchet surfaces. It is numerically shown that the motion of self-propelled Leidenfrost droplets on ratchet surfaces is owing to the asymmetry of the ratchets and the vapor flows beneath the droplets. It is found that the Leidenfrost droplets move in the direction toward the slowly inclined side from the ratchet peaks, which agrees with the direction of droplet motion in experiments [Linke et al., Phys. Rev. Lett., 2006, 96, 154502]. Moreover, the influences of the ratchet aspect ratio are investigated. For the considered ratchet surfaces, a critical value of the ratchet aspect ratio is approximately found, which corresponds to the maximum droplet moving velocity. Furthermore, the processes that the Leidenfrost droplets climb uphill on inclined ratchet surfaces are also studied. Numerical results show that the maximum inclination angle at which a Leidenfrost droplet can still climb uphill successfully is affected by the initial radius of the droplet.

Gene and protein expression in the oxaliplatin-resistant HT29/L-OHP human colon cancer cell line.

Oxaliplatin (L-OHP) is one of the most commonly used anticancer drugs in adjuvant treatment of colon cancer after complete resection of the primary tumor and treatment of metastatic colorectal cancer. Cancer cells eventually become resistant to L-OHP, which diminishes its curative effect. However, the mechanism of action of L-OHP remains unknown. In this study, an L-OHP-resistant human colon cancer cell line, HT29/L-OHP, was established by gradually increasing the dose of L-OHP in culture. The expression levels of the tumor susceptibility gene 101 (tsg101) and the TSG101 protein in HT29 and HT29/L-OHP cell lines were examined by reverse transcription-polymerase chain reaction and western blot analysis. In addition, the expression levels of several apoptosis-regulating protein markers were determined using immunohistochemistry-staining assays. We found that the expression of tsg101 mRNA and of TSG101 protein were significantly higher in the HT29/L-OHP cell line than in its parent, HT29 (P < 0.05). In addition, the expression of multiple apoptosis-regulating protein markers were significantly increased (P < 0.05) in the HT29/L-OHP cell line. These data suggest that these markers could be useful as predictive markers for evaluating and comparing the efficacy and molecular pharmacology of chemotherapeutics.

Tandem overexpression of five human factors renders murine hepatocytes susceptible to hepatitis C virus.

Development of mouse model of hepatitis C virus (HCV) infection has great significance in drug screening and vaccine research. The barriers of interspecies transmission of HCV are increasingly better understood. Human factors, namely low-density lipoprotein receptor (hLDLR), CD81 (hCD81), scavenger receptor class B type I (hSCARB1), occludin (hOCLN) and claudin 1 (hCLDN1) are all required for rendering mouse hepatocytes permissive to HCV. With the aim to humanize mouse hepatocytes we constructed two recombinant vectors tandemly expressing the first three and the last two HCV entry factors mentioned above, respectively. Cotransfection of mouse hepatocytes with these vectors made them permissive to HCV binding and entry. Tandem overexpression of hLDLR, hSCARB1, hCD81, hCLDN1 and hOCLN is a novel approach to tailoring mouse hepatocytes to HCV binding and entry which can be further used to establish a mouse model of HCV infection as a basis for developing antiviral drugs and vaccines.

Cladding pumped few-mode EDFA for mode division multiplexed transmission.

We experimentally demonstrate a few-mode erbium doped fiber amplifier (FM-EDFA) supporting 6 spatial modes with a cladding pumped architecture. Average modal gains are measured to be >20dB between 1534nm-1565nm with a differential modal gain of ~3dB among the mode groups and noise figures of 6-7dB. The cladding pumped FM-EDFA offers a cost effective alternative to core-pumped variant as low cost, high power multimode pumps can be used, and offers performance, scalability and simplicity to FM-EDFA design.

[Effect of deletion of protein 4.1R on proliferation, apoptosis and glycolysis of hepatocyte HL-7702 cells].

OBJECTIVE: To explore the effects of deletion of protein 4.1R on hepatocyte proliferation, apoptosis, and glycolysis and the molecular mechanisms. METHODS: A 4.1R-/- HL-7702 cell line was constructed using CRISPR/Cas9 technique, and with 4.1R+/+HL-7702 cells as the control, its proliferative capacity and cell apoptosis were assessed using CCK-8 assay, EdU-488 staining, flow cytometry and Annexin V-FITC/PI staining at 24, 48, 72 h of cell culture. The changes in glucose uptake, lactate secretion, ATP production and pH value of the culture supernatant of 4.1R-/- HL-7702 cells were determined. The mRNA expressions of the key regulatory enzymes HK2, PFKL, PKM2 and LDHA in glycolysis were detected with qRT-PCR, and the protein expressions of AMPK, p-AMPK, Raptor and p-Raptor were determined using Western blotting. RESULTS: Western blotting and sequencing analysis both confirmed the successful construction of 4.1R-/- HL-7702 cell line. Compared with the wild-type cells, 4.1R-/- HL-7702 cells exhibited a lowered proliferative activity with increased cell apoptosis. The deletion of protein 4.1R also resulted in significantly decreased glucose uptake, lactate secretion and ATP production of the cells and increased pH value of the cell culture supernatant. qRT-PCR showed significantly decreased mRNA expressions of the key regulatory enzymes in glycolysis in 4.1R-/- HL-7702 cells. Compared with those in HL-7702 cells, the expression levels of AMPK and Raptor proteins were decreased while the expression levels of p-AMPK and p-Raptor proteins increased significantly in 4.1R-/- HL-7702 cells. CONCLUSION: Deletion of protein 4.1R in HL-7702 cells results in reduced proliferative capacity, increased apoptosis and suppression of glycolysis, and this regulatory mechanism is closely related with the activation of the downstream AMPK-mTORC1 signaling pathway.

Three mode Er3+ ring-doped fiber amplifier for mode-division multiplexed transmission.

We successfully fabricate three-mode erbium doped fiber with a confined Er(3+) doped ring structure and experimentally characterize the amplifier performance with a view to mode-division multiplexed (MDM) transmission. The differential modal gain was effectively mitigated by controlling the relative thickness of the ring-doped layer in the active fiber and pump launch conditions. A detailed study of the modal gain properties, amplifier performance in a MDM transmission system and inter-modal cross-gain modulation and associated transient effects is presented.

Predictive value of endometrial receptivity evaluated by three-dimensional ultrasound in ectopic pregnancy after in vitro fertilization-embryo transfer.

OBJECTIVE: The aim of this study was to use three-dimensional (3D) ultrasound to detect ultrasound parameters related to the uterine artery and endometrium, evaluate endometrial receptivity, and investigate the predictive value of each parameter for ectopic pregnancy (EP) after in vitro fertilization-embryo transfer (IVF-ET). PATIENTS AND METHODS: Fifty-seven cases of pregnancy following IVF-ET in our institution were collected and split into EP and intrauterine pregnancy (IP) groups based on the location of pregnancy, with 27 cases in EP and 30 cases in IP. Endometrial thickness, type, volume, endometrial blood flow parameters, and uterine artery blood flow parameters were all measured one day before transplantation in both groups, and the differences between the two groups were examined. RESULTS: There were differences in endometrial blood flow typing between the two groups, with type III endometrium accounting for the highest proportion in both; the uterine spiral artery pulsatility index PI was significantly higher in the EP group than in the IP group; there were no statistical differences in uterine volume, uterine artery resistance index mRI, or uterine artery resistance index S/D between the two groups; there were no statistical differences in uterine volume, or uterine artery. CONCLUSIONS: Intracavitary 3D ultrasound can assess endometrial tolerance and may predict pregnancy outcome after IVF-ET.

FOXN2 suppresses the proliferation and invasion of human hepatocellular carcinoma cells.

OBJECTIVE: The aim of this study was to explore the roles of FOXN2 (Fork head Box N2) in mediating the proliferation and invasion of hepatocellular carcinoma (HCC) cells. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to determine expression of FOXN2 in HCC tissues and cells. Transfection of plasmid containing FOXN2 was used to exogenously overexpress FOXN2 in vitro. Cell Counting Kit-8 (CCK-8) assay and transwell assay were applied to detect the proliferation and invasion of HCC cells, respectively. RESULTS: FOXN2 expression decreased significantly in both HCC tissues and cells (p<0.05). Upregulation of FOXN2 significantly inhibited the proliferation and invasion of HCC cells (p<0.05). CONCLUSIONS: FOXN2 acts as a regulator in the progression of HCC. Our findings suggest that FOXN2 may be a novel therapeutic monitoring and prognosis biomarker in HCC.

Design and evaluation of quantum dot sensors for making superficial x-ray energy radiation measurements.

The extraordinary physical properties of quantum dot (QD) materials such as high radiation sensitivity and good radiation resistivity indicate their potential for use in the fabrication of radiation sensors. This paper reports the design and fabrication of two kinds of radiation sensors based on ZnO and CdTe QDs. Both sensors are characterized using a Gulmay Medical D3000 DXR unit for superficial x-ray irradiation with source photon energies that range from 36.9 to 64.9 keV. The QD radiation sensors exhibit excellent linearity with respect to different photon energy doses, radiation source to device surface distances, and field sizes. The effects of the electrode separation and the area density of the QD layer are also investigated. All sensors characterized show an outstanding repeatability under photon irradiation, with a signal variation less than 1%.

[Association of sleep with anxiety in the elderly aged 60 years and older in China].

Objective: To investigate the relationship of sleep duration and sleep quality with anxiety in the elderly aged 60 years and older in China. Methods: The elderly aged 60 years and older were selected from the China Short-term Health Effects of Air Pollution Study conducted between July 18, 2017 and February 7, 2018. Multivariate logistic regression models were used to analyze the association of sleep duration and sleep quality with anxiety. Results: A total of 3 897 elderly aged 60 years and older were included in the study. The age of the elderly was (73.4±8.0) years old. Among the elderly surveyed, 6.5% were defined with anxiety, and 18.7% reported poor sleep quality. Multivariate logistic regression models showed shorter sleep duration was the risk factor for anxiety in the elderly that after adjusting for factors such as general demographics, socioeconomic factors, lifestyle, health status, social support and ambient fine particulates exposure. Compared with the elderly with 7 hours of sleep duration daily, the OR (95%CI) of anxiety for those with sleep duration ≤ 6 hours was 2.09 (1.49-2.93). Compared with those with good sleep quality, the OR (95%CI) of anxiety for those with poor sleep quality was 5.12 (3.88-6.77). We also found statistically significant correlations of the scores of subscales of Pittsburgh sleep quality index with anxiety, in which the effects of sleep disturbance, subjective sleep quality and daytime dysfunction scores were most obvious, the ORs (95%CI) were 4.63 (3.55-6.04), 2.75 (2.33-3.23) and 2.50 (2.19-2.86), respectively. Subgroup analysis showed that the association of sleep duration and sleep quality with anxiety was more obvious in males and in those aged <80 years. Conclusion: Shorter sleep duration and poor sleep quality are associated with anxiety in the elderly in China.

[Influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China].

Objective: To analyze influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China. Methods: We recruited 2 180 participants aged 65 years and older in 8 longevity areas from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey in 2017. Multivariate logistic regression analysis was performed to evaluate the relationships of socio-demographic characteristics, behavioral lifestyle, chronic disease prevalence, functional status, family and social support with depressive symptoms in the elderly. Results: The detection rate of depression symptoms was 15.0% in the elderly aged 65 years and older in 8 longevity areas of China, and the detection rate of depression symptoms was 11.5% in men and 18.5% in women. Multivariate logistic regression analysis results showed that the detection rate of depressive symptoms was lower in the elderly who had regular physical exercises (OR=0.44, 95%CI: 0.26-0.74), frequent fish intakes (OR=0.57, 95%CI: 0.39-0.83), recreational activities (OR=0.65, 95%CI: 0.44-0.96), social activities (OR=0.28, 95%CI: 0.11-0.73) and community services (OR=0.68, 95%CI: 0.50-0.93). The elderly who were lack of sleep (OR=2.04, 95%CI: 1.49-2.80), had visual impairment (OR=1.54, 95%CI: 1.08-2.18), had gastrointestinal ulcer (OR=2.97, 95%CI: 1.53-5.77), had arthritis (OR=2.63, 95%CI: 1.61-4.32), had higher family expenditure than income (OR=1.80, 95%CI: 1.17-2.78) and were in poor economic condition (OR=4.58, 95%CI: 2.48-8.47) had higher detection rate of depressive symptoms. Conclusion: The status of doing physical exercise, fish intake in diet, social activity participation, sleep quality or vision, and the prevalence of gastrointestinal ulcers and arthritis were associated with the detection rate of depressive symptoms in the elderly.

[Prediction of 6-year incidence risk of chronic kidney disease in the elderly aged 65 years and older in 8 longevity areas in China].

Objective: To establish a prediction model for 6-year incidence risk of chronic kidney disease (CKD) in the elderly aged 65 years and older in China. Methods: In this prospective cohort study, we used the data of 3 742 participants collected during 2008/2009-2014 and during 2012-2017/2018 from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey. Two follow up surveys for renal function were successfully conducted for 1 055 participants without CKD in baseline survey. Lasso method was used for the selection of risk factors. The risk prediction model of CKD was established by using Cox proportional hazards regression models and visualized through nomogram tool. Bootstrap method (1 000 resample) was used for internal validation, and the performance of the model was assessed by C-index and calibration curve. Results: The mean age of participants was (80.8±11.4) years. In 4 797 person years of follow up, CKD was found in 262 participants (24.8%). Age, BMI, sex, education level, marital status, having retirement pension or insurance, hypertension prevalence, blood uric acid, blood urea nitrogen and total cholesterol levels and estimated glomerular filtration rate in baseline survey were used in the model to predict the 6-year incidence risk of CKD in the elderly. The corrected C-index was 0.766, the calibration curve showed good consistence between predicted probability and observed probability in high risk group, but relatively poor consistence in low risk group. Conclusion: The incidence risk prediction model of CKD established in this study has a good performance, and the nomogram can be used as visualization tool to predict the 6-year risk of CKD in the elderly aged 65 years and older in China.

Human neural stem cell transplantation attenuates apoptosis and improves neurological functions after cerebral ischemia in rats.

BACKGROUND: Neuroprotection is a major therapeutic approach for ischemic brain injury. We investigated the neuroprotective effects induced by transplantation of human embryonic neural stem cells (NSCs) into the cortical penumbra 24 h after focal cerebral ischemia. METHODS: NSCs were prepared from human embryonic brains obtained at 8 weeks of gestation. Focal cerebral ischemia was induced in adult rats by permanent occlusion of the middle cerebral artery. Animals were randomly divided into two groups: NSCs-grafted group and medium-grafted group (control). Infarct size was assessed 28 days after transplantation by hematoxylin and eosin staining. Neurological severity scores were evaluated before ischemia and at 1, 7, 14, and 28 days after transplantation. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and immunohistochemical analysis of Bcl-2 and Bax were performed at 7, 14, and 28 days after transplantation. RESULTS: Physiological parameters of the two groups were comparable, but not significantly different. NSC transplantation significantly improved neurological function (P<0.05) but did not reduce the infarct size significantly (P>0.05). Compared with the control, NSC transplantation significantly reduced the number of TUNEL- and Bax-positive cells in the penumbra at 7 days. Interestingly, the number of Bcl-2-positive cells in the penumbra after NSC transplantation was significantly higher than that after medium transplantation (P<0.05). CONCLUSIONS: The results indicate that NSC transplantation has anti-apoptotic activity and can improve the neurological function; these effects are mediated by the up-regulation of Bcl-2 expression in the penumbra.

Experimental investigation on bubble coalescence under nonuniform temperature distribution in reduced gravity.

Results on bubble coalescences from the space experiment of thermocapillary bubble migration conducted on board the Chinese 22nd recoverable satellite are presented in this paper. Some coalescences of large spherical bubbles under microgravity are observed through bubbles staying at the upper side of the test cell. The data of bubble coalescence time are recorded and compared with theoretical predictions, which is based on a theory to describe the tendency of coalescence connected to chemical potential difference. It is implied that the theory is applicable for the experimental data of bubble coalescence. Moreover, the angle between the line of two bubble centers and temperature gradient falled mostly in the range 20 degrees -40 degrees .