Through the suvey, we find that freshmen are generally suited for college physics studies. ln this paper, high school and college students’ interest in Learnig, their initiatives, the change of their study methods and the teachers’ teaching methods are discussed.

The phytase was extracted from solid state leavening of Trichoderma Viride LH374.The crude product was purified by(NH_4)_2SO_4 precipitation,gel filtration and ion exchange chromatography.The purified phyatse was 13.3 times of the raw products,and the extraction ration was 27.1%.The study on the enzymology of phyatse showed that the optimal temperature and pH were 55℃ and 6.0,respectively.The Km value of the phytase was 0.15mmol/L.

Objective To investigate the expression and significance of heme oxygenase-1(HO-1) in gastric adenocarcinoma and its peritoneal metastatic tissues, as well as drug-resistant cell strains. Methods The expression of HO-1 in patients with (n=68) or without (n=46) peritoneal metastasis of gastric adenocarinoma was examined. The expression of HO-1 in cancerous tissue, peritoneal metastatic foci, and normal peritoneum was detected by immunohistochemistry. The expression of HO-1 protein in metastatic foci and drug-resistant cell strains was measured by Western blotting. Results The positive expression of HO-1 was 39.7% (27/68) in gastric adenocarcinoma tissues with metastasis and 41.2% (28/68) in peritoneal metastatic tissues, which was significantly higher than that in normal peritoneum (0%,0/68,P<0.01) and gastric adenocarcinoma tissues without metastasis (21.7%, 10/46, P<0.05). The Western blot study showed that the HO-1 expression in metastatic tissues was higher than that in normal peritoneum (P<0.05). The expression of HO-1 protein was markedly increased in GC9811-P drug-resistant cell strains compared with its parental cell strains (P<0.05). Conclusions The increased expression of HO-1 may be involved in the peritoneal metastasis of gastric adenocarcinoma, and related to the malignant potential. The underlying signal pathways in neopastic epithelium may also be related to the multi-drug resistance.

Objective To observe the expression of hypoxia inducible faetor-1α (HIF-1α) in the retina of rabbits with acute high intraocular pressure and to investigate the mechanism of systemic domestic recombinant human erythropoietin (rhEPO) protecting the retina from ischemia-reperfusion injury. Methods First, control group and model group were established in rabbit eyes. The acute high intraocular pressure model was established by saline perfusion into anterior chamber, and then hypodermic injection of domestic rhEPO was made. HIF-1α protein in the retina was observed by immunohistochemical staining method on days 1, 3, 7 and 14 after retinal ischemla-reperfusion, respectively. Results No cells with HIF-la positive expression were observed in the retina of the control group. Ceils with HIF-1α positive expression in the model group outnumbered those in the control group (P < 0. 01). The resemblance pattern occurred in EPO group but its degree was slightly greater than that in the model group from day 3 after ischemia-reperfusion (P<0.05). Conclusion Domestic rhEPO can down-regulate the expression of HIF-1α in the retina with acute high intraocular pressure, which may be one of the mechanisms that rhEPO protects the retina from ischemia-reperfusion injury.

AIMTo establish the RP-HPLC fingerprint analysis for the quality control of Radix Angelicae dahuricae.

METHODSHPLC fingerprint analysis method of Radix Angelicae dahuricae was developed. Kromasil C18 column (250 mm x 4.6 mm ID, 5 microm) was used, with mixture of acetonitrile and water as mobile phase in a gradient mode. The flow rate was 1.0 mL x min(-1). The wavelength of measurement was 254 nm. Twenty-one batches of Radix Angelicae dahuricae were determined.

RESULTSThe 21 samples were classified as 4 clusters by cluster analysis and the 11 superior in producing area samples were confirmed to establish the mutual model. The samples' quality was assessed by Similarity Evaluation System for Chromatographic Fingerprint of TCM 2004.

CONCLUSIONThe method can be used to identify and evaluate the quality of Radix Angelicae dahuricae conveniently.

Angelica ; chemistry ; Chromatography, High Pressure Liquid ; methods ; Cluster Analysis ; Plant Extracts ; analysis ; chemistry ; standards ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Quality Control ; Reproducibility of Results

Registration and approval is a necessary step in product marketing process of new medical devices to ensure their safety and efficiency.At present,many countries are relatively strict in the management of high risk medical devices,especially for class Ⅲ medical devices.Taking clinical trials as examples,they cost too many human,material resources.FDA has introduced a variety of regulations and policies to streamline the registration process to speed up the product marketing process.Based on the introduction of the relevant regulations on the exemption in parts of medical device registration and approval process in the United States,this paper compares and analyzes the simplified status of medical device approval in China.In the end,the significance of exemption in the registration and approval process is expounded,and some suggestions on how to optimize and approve the registration and approval process of medical devices in China are put forward.
China ; Device Approval ; Humans ; Registries ; United States ; United States Food and Drug Administration

OBJECTIVETo observe the therapeutic effect and major complications of haploidentical nonmyeloablative allogeneic peripheral blood stem cell transplantation (NST) for refractory or relapsed leukemia.

METHODSThe results of 30 patients, including 14 cases of acute myeloid leukemia (AML), 11 cases of acute lymphoblastic leukemia (ALL), 5 case of chronic myelogenous leukemia (CML) (accelerated and blastic phase) with refractory or relapsed leukemia (RF/RL) who underwent haploidentical NST from August 2000 to April 2009 were analyzed. The conditioning regimen consisted of fludarabine (flu), antithymocyte globulin (ATG), cyclophosphamide (CTX), total body irradiation (TBI) and cytarabine (Ara-C) or myleran (Bu). Graft-versus-host disease (GVHD) prevention programmes consisted of Cyclosporine (CsA), mycophenolate mofetil (MMF), CD25 monoclonal antibody combined with mesenchymal stem cells (MSC).

RESULTSTwenty six cases of patients were full donor engraftment and 4 cases mixed chimerism into full donor chimerism. The average duration of neutrophil >0.5×10⁸/L after NST was 11 (9-16) days, and platelet >20×10⁸/L 17 (12-60) days. Upon follow-up of 16 to 120 months, 12-month transplant-related mortality (TRM) was 46.7%, acute Ⅱ-Ⅳgraft-versus-host disease (aGVHD) incidence was 40.0%. The probability of 3-year disease relapse, EFS and overall survival (OS) rates were 16.7%, 46.2% and 50.0% respectively.

CONCLUSIONHaploidentical NST could improve OS and EFS of refractory or relapsed leukemia and reducce TRM to some extent.

Adolescent ; Adult ; Child ; Disease-Free Survival ; Female ; Follow-Up Studies ; Hematopoietic Stem Cell Transplantation ; methods ; Humans ; Leukemia ; therapy ; Male ; Middle Aged ; Recurrence ; Retrospective Studies ; Survival Rate ; Treatment Outcome ; Young Adult

To explore hemorrhage risk and the clinical significance of abnormal change of prothrombin time (PT), activated partial thromboplastin time (APTT), plasma fibrinogen (FIB), plasma thrombin time (TT) and d-dimer (D-D) in de novo acute leukemia (except for APL), the different bleeding manifestations of 114 cases of de novo acute leukemia with different coagulation indexes were analyzed retrospectively. The correlation between these blood coagulation indexes and the possible correlative clinical characteristics were analysed, including age, sex, type of acute leukemia, initial white blood cell(WBC) and platelet(Plt) count, the proportion of blast cells in bone marrow and cytogenetic abnormality of patients at diagnosis. The results indicated that the incidence of abnormal blood coagulation was as high as 78.1% for de novo AL patients. These patients with 5 normal blood coagulation indexes may have mild bleeding manifestation, but the more abnormal indexes, the more severe bleeding. Both PT and D-D were sensitive indexes for diagnosis of level II bleeding. Incidence of abnormal blood coagulation significantly correlates with the proportion of blast cells in bone marrow (χ(2) = 4.184, OR = 1.021, P < 0.05) and more with D-D (P < 0.01), while age, sex, type of AL, WBC count, Plt count and abnormality of cytogenetics did not correlate with abnormal blood coagulation. It is concluded that the coagulation and fibrinolysis are abnormal in most patients with de novo acute leukemia. More abnormal indexes indicate more severe bleeding, and both PT and D-D are sensitive indexes for diagnosis of level II bleeding. Higher proportion of blast cells in bone marrow predicts higher incidence of abnormal blood clotting. Acute leukemia with elderly age, high white blood cell count and adverse cytogenetics do not predict severer abnormal blood clotting. Detection of PT, APTT, TT, FIB, and D-D may help to judge whether the patients are in a state of hypercoagulability or disseminated intravenous coagulation, which will provide experiment evidences for early intervention and medication.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Blood Coagulation ; Blood Coagulation Tests ; Child ; Female ; Fibrin Fibrinogen Degradation Products ; Hemorrhage ; pathology ; Humans ; Leukemia ; blood ; pathology ; Leukocyte Count ; Male ; Middle Aged ; Platelet Count ; Prothrombin Time ; Retrospective Studies ; Thrombin Time ; Young Adult

BACKGROUNDOver past two decades, vagus nerve stimulation (VNS) has been widely used and reported to alleviate seizure frequency worldwide, however, so far, only hundreds of patients with pharmaco-resistant epilepsy (PRE) have been treated with VNS in mainland China. The study aimed to evaluate the effectiveness of VNS for Chinese patients with PRE and compare its relationship with age cohort and gender.

METHODSWe retrospectively assessed the clinical outcome of 94 patients with PRE, who were treated with VNS at Beijing Fengtai Hospital and Beijing Tiantan Hospital between November 2008 and April 2014 from our database of 106 consecutive patients. The clinical data analysis was retrospectively examined.

RESULTSSeizure frequency significantly decreased with VNS therapy after intermittent stimulation of the vagus nerve. At last follow-up, we found McHugh classifications of Class I in 33 patients (35.1%), Class II in 27 patients (28.7%), Class III in 20 patients (21.3%), Class IV in 3 patients (3.2%), and Class V in 11 patients (11.7%). Notably, 8 (8.5%) patients were seizure-free while ≥50% seizure frequency reduction occurred in as many as 60 patients (63.8%). Furthermore, with regard to the modified Engel classification, 12 patients (12.8%) were classified as Class I, 11 patients (11.7%) were classified as Class II, 37 patients (39.4%) were classified as Class III, 34 patients (36.2%) were classified as Class IV. We also found that the factors of gender or age are not associated with clinical outcome.

CONCLUSIONSThis comparative study confirmed that VNS is a safe, well-tolerated, and effective treatment for Chinese PRE patients. VNS reduced the seizure frequency regardless of age or gender of studied patients.

Adolescent ; Adult ; Child ; Child, Preschool ; Drug Resistance ; Epilepsy ; therapy ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Treatment Outcome ; Vagus Nerve Stimulation ; methods ; Young Adult

OBJECTIVETo explore immunoregulatory mechanism of mesenchymal stem cells (MSCs) in H-2 haploidentical bone marrow cells transplantation mice.

METHODSBALB/c female mice irradiated with 8Gy 60Co gamma-rays were divided into two groups: MSCs group, infused cm-DiI labeled MSCs from female CB6F1 mice and monocytes from the bone marrow and spleen of male CB6F1; Control group, only infused monocytes from the bone marrow and spleen of male CB6F1. T-lymphocyte subpopulation of peripheral blood cells, T and B cells proliferation stimulated by ConA and LPS, mixed lymphocyte reaction between donor and recipient and third part, the sry-gene chimerism of bone marrow, spleen and thymus of the recipient, the distribution of MSCs in the recipient, the incidence rate of GVHD and survival were observed.

RESULTSThe CD3 at +90 d the percent of CD3+ CD4+ cells, and CD4/CD8 at +30 d in the MSCs group were higher than that in control post-transplantation, respectively (P < 0.05). The proliferation activity of B cells recovered more rapidly and that of T cells recovered comparably in MSCs group as compared with that in control group. The result of MLR between donor and recipient was lower in MSCs group than that in the control; and that between recipient and the third part had no difference. The sry-gene chimerism of bone marrow and spleen of the recipient was higher in MSCs group than in control at +30 d. The MSCs mainly distributed in intestine, thymus, bone marrow, liver, heart of the recipient after transplantation. The incidence of acute GVHD was higher and the survival rate was lower in MSCs group than that in control group (P < 0.05). Chronic GVHD occurred in the control group at +90 d, while in the MSCs group at +120 d.

CONCLUSIONSMSCs might improve stem cell engraftment, promote lymphocyte and humoral immunity recovery, decrease incidence of GVHD and increase survival by inducing specific immunologic tolerance and repairing organs injuries.

Animals ; Bone Marrow Cells ; immunology ; Bone Marrow Transplantation ; immunology ; Female ; Graft vs Host Disease ; immunology ; Male ; Mesenchymal Stromal Cells ; immunology ; Mice ; Mice, Inbred BALB C