Quantum Dots (QDs) with its unique optical properties including broad-range excitation, sizetunable narrow emission spectra and the adjustable emission wavelength by changing the size of core composition, is widely applied in biomedicine as a fluorescent marker in recent years. This paper focuses on the review of the characteristic of ODs, the prospects of its applications in biological and medical areas and the latest research development.Moreover,key issues including the potential toxicity of ODs are discussed.

AIM: To observe the enhanced green fluorescent protein (EGFP) gene expression and cytotoxicity in human adipose derived adult stem cells (hADSCs) by pEGFP-N1, Ad5-EGFP and rAAV-2/1-EGFP, and investigate the suitable gene-transferred vehicle. METHODS: The experiment was conducted at Chinese National Human Genome Center and the Third Hospital of Peking University from January to July 2006. ①After the patients and their relative were informed consent, the subcutaneous adipose tissue was obtained from the patients undergoing routine total hip joint replacement in Department of Orthopaedics, Third Hospital of Peking University. pEGFP-N1 was provided by Clotech Company, Ad5-EGFP and rAAV-2/1-EGFP by Vector Gene Technology Company. ②hADSCs were cultured in vitro after isolated from the adipose tissue after dissected and digested with type I collagenase. ③hADSCs of passage 3 were infected with pEGFP-N1, Ad5-EGFP and rAAV-2/1-EGFP and the EGFP expression and the cell toxicity were observed. ④Twenty-four hours after being transfected, 5?104 cells were reseeded in a 24-well plate and the solution was changed three times every week. The growth curves of each group were drawn. Normal non-transfected cells served as control. The influence of different transfection ways on the growth of hADSCs was observed. RESULTS: ①Comparison of transfected efficiency with different ways: pEGFP-N1 transfection showed a higher cytotoxicity and lower efficiency of 10.5%; Ad5-EGFP could efficiently transfect hADSCs (multiplicity of infection=5?102, 82.5%); when MOI was 0.05); however, the growth capability of hADSCs was decreased significantly in the pEGFP-N1 transfection group compared with the control, and the differences were significant at day 3-10 after transfection (P

The design and efficacy of surgery for horizontal idiopathic nystagmus (HIN) with abnormal head posture and strabismus were investigated. Different surgical procedures were selected according to the angle of head turn in 44 cases of HIN with abnormal head posture and strabismus. For patients with a head turn of 15° or less, the Anderson procedure was used; the yoke muscles were recessed upon slow-phase. For patients with a head turn between 15° and 25°, the surgery was designed as a Kestenbaum 5-4-4-5 procedure. For patients with a head turn of 25° or more, the surgery was designed as a Parks 5-8-6-7 procedure. The surgery to correct the abnormal head posture was performed on the fixating eye while that to correct the deviation was then performed on the non-fixating eye at the same time. The amount of surgery of the horizontal rectus muscles on the non-fixating eye was sum of the angle of head turn and the degree of deviation, which was calculated as follows: recession/resection amount of medial and lateral rectis/2×5=angle of head turn±degree of deviation. The results showed as follows: (1) Visual acuity: the visual acuity in the primary ocular position increased two lines or more in 35 patients, accounting for 79.55%. Nine patients had no or only one-line improvement, accounting for 20.45% of the entire study population; (2) The degree of deviation in the primary ocular position: 37 cases had a normal primary ocular position or the degree of deviation ≤8(δ) after surgery, accounting for 84.09%. Six patients had a residual degree of deviation of 8(δ)-15(δ), accounting for 13.64%. One patient had a residual degree of deviation >20(δ), accounting for 2.27% of the patients examined; (3) Abnormal head posture: 34 patients had a normal head posture or a head turn of less than 5°, accounting for 72.27%. Eight patients had a residual head turn of 5°-15°, accounting for 18.18%. Two patients had a head turn of 15°-25°, accounting for 4.55%. It was concluded that different surgical procedures based on the angle of head turn and the relationship between deviation and null zone can eliminate anomalous head posture, correct deviation, and improve vision acuity in the primary ocular position.

Objective To analyze the value of multi-slice spiral CT (SCT) scan in staging and subtyping of renal cell carcinoma (RCC). Methods The preoperative kidney SCT data and postoperative pathology results of 64 patients with RCC were retrospectively analyzed. The patients′ ages ranged from 33-78 years (average 54 years). There were 44 males and 20 females in the study group. According to the CUA Guidelines, the staging and subtyping of RCC were performed through the combined information of preoperative SCT attenuation in unenhanced, corticomedullary phase and enhancement pattern. The results were compared with the postoperative histopathological results. Results The SCT results showed 38 cases were clear cell RCC, 14 cases were papillary RCC and 12 cases were chromophobic cell RCC. Histopathological results showed that 40 cases were clear cell RCC, 16 cases were papillary RCC and 8 cases were chromophobic cell RCC. According to the standard of 40 HU of CT attenuation value, the sensitivity, specificity and accuracy were 75%, 79% and 78% for diagnosis of papillary RCC in the unenhanced phase. The sensitivity, specificity and accuracy by the standard of 90 HU of CT attenuation value was 90%, 88% and 89% for diagnosis of clear cell RCC in the corticomedullary phase. In chromophobic RCC, homogeneous enhancement was more common than in papillary RCC and clear cell RCC. There was no significant difference of staging and subtyping of RCC between SCT and pathological results (P>0.05). The accuracy of SCT in staging and subtyping of RCC was 88% in staging, and 89% in subtyping. Conclusions SCT is a useful preoperative tool to stage and subtype RCC

BACKGROUND: Mortality related to cardiopulmonary bypass can be lowered by intra-operative monitoring system.Monitoring liquid level and pressure is extremely indispensable for examination of cardiopulmonary bypass(CPB).OBJECTIVE: To design a CPB safety system including an arterial line pressure monitor and low-level sensor,and to evaluate its safety and effects in clinical settings.METHODS: The safety system was composed of pressure transducer,photoelectric transmitter,photoelectric detector,core controller,and liquid crystal display.The principles of reflection and refraction were applied to the design of level sensor.The pressure measurements were converted into electronic signals and processed.According to two principles above-mentioned,fluid level detector and pressure monitor were designed.Thirty patients with the age of 1-75 years receiving cardiac surgery with cardiopulmonary bypass were enrolled.The arterial line pressure at different pump flows was measured and the alarm function of the level sensor was also validated.RESULTS AND CONCLUSION: Cardiopulmonary bypass arterial line pressure increased with the pump flow.Arterial line pressure detected by HZ-01-A safety system also increased with the pump flow increasing,which was highly related to the pump pressure.HZ-01-A safety system could alarm when the arterial line pressure and reservoir level exceeded the pre-determined thresholds.HZ-01-A safety system could be safely and effectively applied to clinical cardiopulmonary bypass and improve bypass safety by accurately detecting the pressure and reservoir level.

Objective To build rat DVT inferior vena cava partial stasis (narrow) model, to detected the expression ofβ2-GP1, VEGF and TF in rat blood, and to investigat the correlation betweenβ2-GP1, VEGF and TF with DVT. Meth?ods SD rats (n=70) are divided into control group (n=10), sham operation group (n=30) and the model group (n=30) ran?domly and DVT model was built by the inferior vena cava partial stasis (narrow) after 2 h, 8 h and 24 h respectively. In each time point, ten rats were taken in each group, inferior vena cava blood were collected whileβ2-GP1, VEGF and TF expres?sion were detected by ELISA. Results In rat experiment, compared with control group, there was no significant change in?expression of β2-GP1, VEGF and TF in sham operation group (P > 0.05). Levels of β2-GP1, VEGF and TF were in?creased at the 2nd hour and 8th hour then peak at the 24th hour which was higher than those in the 24th hour control group and in Sham group and it was also higher than those in the 2nd hour and the 8th hour in model group with statistical signifi?cant difference (P<0.01). Conclusion Based on the above experimental data, in rat DVT formation process, β2-GP1, VEGF and TF may play an important role in promote DVT formation.

Objective To investigate the effects of Astragalus Polysaccharide (for intravenous injection) in stimulating the secretion of hematopoietic growth factors from activated human peripheral blood mononuclear cells (PBMC). Methods Human PBMC were isolated from concentrated leukocytes and were cultured with Astragalus Polysaccharide. Hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the supernatant were determined by enzyme-linked immunosorbent assay (ELISA). Results Astragalus Polysaccharide stimulated G-CSF and GM-CSF formation in a dose-dependent and a dose-effect and time-dependent manner. Conclusion Astragalus Polysaccharide can stimulate the secretion of hematopoietic growth factors from activated human PBMC, indicating its clinical application for leukocytopoiesis.

The number of clinical postgraduates is growing with the reform of educational mode of postgraduates.It is a particular concern for medical colleges to improve educational quality of postgraduates,especially to cultivate postgraduates with great ability of observational study.The ability of clinical thinking and observational study is a key objective throughout postgraduate teaching.A good teaching method plays an important role in improving the ability of observational study for clinical postgraduates.A teaching platform combining academic theories with clincal pratice is a basis for promoting quality of clinical postgraduates.The construction of tutor team is a key point in elevating clinical observational ability.Academic exchange is a shortcut to cultivate postgraduates with great observational ability in clinical work.