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BACKGROUND Histone H2A deubiquitinase MYSM1 has recently been shown to be essential for hematopoiesis and hematopoietic stem cell (HSC) function in both mice and humans. However, conventional MYSM1 knockouts cause partial embryonic lethality and growth retardation, and it is difficult to convincingly remove the effects of environmental factors on HSC differentiation and function. MATERIAL AND METHODS MYSM1 conditional knockout (cKO) mice were efficiently induced by using the Vav1-cre transgenic system. The Vav-Cre MYSM1 cKO mice were then analyzed to verify the intrinsic role of MYSM1 in hematopoietic cells. RESULTS MYSM1 cKO mice were viable and were born at normal litter sizes. At steady state, we observed a defect in hematopoiesis, including reduced bone marrow cellularity and abnormal HSC function. MYSM1 deletion drives HSCs from quiescence into rapid cycling, and MYSM1-deficient HSCs display impaired engraftment. In particular, the immature cycling cKO HSCs have elevated reactive oxygen species (ROS) levels and are prone to apoptosis, resulting in the exhaustion of the stem cell pool during stress response to 5-FU. CONCLUSIONS Our study using MYSM1 cKO mice confirms the important role of MYSM1 in maintaining HSC quiescence and survival.

以蔗渣为原料, 以ZnCl 2 为活化剂制备出活性炭AC, 并用KOH对活性炭AC进行二次活化制备活性炭KAC。用热重法测定材料的CO 2 吸附脱附性能, 傅里叶红外光谱、氮气物理吸附–脱附和扫描电镜对样品进行表征。结果表明：KAC具有优异的CO 2 吸附性能, 在60℃下其对CO 2 吸附量可达3.45 mmol/g, 而AC的CO 2 吸附量仅有1.79 mmol/g。KAC的CO 2 吸附能力明显优于AC。循环吸附脱附的结果表明, 经过5次吸附–脱附, 材料的吸附量无显著变化, 表明材料具有良好的再生性能。傅里叶红外分析结果表明两种活性炭材料的特征峰基本一致, 活性炭表面官能团中羟基和羧基可以使活性炭表面的极性增大。氮气物理吸附–脱附和扫描电镜结果表明材料都具有发达的孔径结构, 但KAC的孔径结构比AC更发达, 因此其对CO 2 的吸附能力也更强。

A compact laser diode-pumped solid-state Nd:LuVO4 acousto-optic Q-switched laser is demonstrated at 916 nm of a quasi-three level for the first time. A pulse width of 130 ns is observed when the pulse-repetition frequency is 10 kHz. The laser experiment shows that the Nd:LuVO4 crystal can be used for efficient diode-pumped Q-switched lasers.

Aim of the study Hepatocellular carcinoma suppressor 1 (HCCS1) has been identified as a tumor suppressor gene in the high-frequency loss of heterozygosity (LOH) region on chromosome 17p13.3 in hepatocellular carcinoma (HCC). There was also a high frequency of LOH on chromosome 17p13.3 in non-small cell lung cancer (NSCLC). Therefore, the aim of this study was to explore the expression of HCCS1 in NSCLC as well as its clinical significance. Material and methods Real-time PCR and immunohistochemistry were performed to detect the expression level of HCCS1 mRNA and protein in NSCLC and noncancerous tissues, respectively. Further, we explored the relationship between HCCS1 expression and various clinical features in NSCLC. Results The mRNA and protein expression of HCCS1 were both significantly lower in NSCLC samples than those in noncancerous tissues. That is, the mRNA level of HCCS1 was 0.0044 ±0.0036 and 0.0067 ±0.0054 in NSCLC samples and noncancerous tissues, respectively. The protein level of HCCS1 was 4.67 ±1.15 and 6.13 ±1.24 in NSCLC samples and noncancerous tissues, respectively. Importantly, this difference in expression was significantly correlated with tumor lymph node metastasis (TNM) in NSCLC (p < 0.05), but not with gender and age of the patients, pathological types, TNM stages, or grades of cancers (p > 0.05). Conclusion Our results suggest that HCCS1 may be involved in NSCLC carcinogenesis.

Study of LD pumped single longitudinal mode Cr,Tm,Ho∶YAG microchip laser pumped by a 785?nm laser diode（LD） is reported. The pump threshold power of the Cr,Tm,Ho∶YAG microchip laser was 1060?mW and the maximum single longitudinal mode output power was 31?mW. The output power against the laser crystal temperature demonstrated the temperature sensitivity of Cr,Tm,Ho∶YAG crystal. The frequency tuning property of the Cr,Tm,Ho∶YAG microchip laser was also measured by changing the temperature of the crystal, and a tuning coefficient of 14?GHz/℃ was obtained.

The twisted stigmatic beam with orbital angular momentum generated by transforming the Hermite-Gaussian beam through a rotated cylindrical lens system was studied. By utilizing of method of mode decomposition, the theory of transformation was analyzed. The transfer of orbital angular momentum during beam transformation was analyzed using beam transforming matrix and Collins integral. It was found that the angular momentum transfer takes place at the first cylindrical lens and remains constant after that.