我国香烟生产消费的特点与增收香烟税

国际经验表明,增收香烟税是最有效的控烟手段之一。本文在肯定提高香烟税的必要性的基础上,总结了中国香烟生产和消费的特点,以及这些特点对于增收香烟税预期效果的影响,并针对这些问题提出相应的对策思路,以保证增收香烟税能够在最大程度上达到预期的效果。     

Assessment of ascending aortic elasticity in hypertension patients by quantitative tissue velocity imaging

The elasticity of the ascending aorta in healthy volunteers and hypertension patients were examined by using quantitative tissue velocity imaging （QTVI）, and the age-related change in the as-cending aortic elasticity was investigated. The anterior and posterior walls of the ascending aorta were imaged with tissue Doppler method in all the subjects and QTVI was performed. Stable curves were obtained from 173 hypertension patients and 185 healthy adults. The peak early diastolic veloc-ity （Ve）, peak late diastolic velocity （Va） and peak systolic velocity （Vs） were measured. The relation of age with these measures was assessed. The results showed that the elasticity of the ascending aorta was much lower in the hypertension patients than in normal controls （P〈0.05）, and the elasticity was decreased with age in both groups （P〈0.05）. Our results suggested that QTVI, a new non-invasive ul-trasonic technique, is helpful for the assessment of the aortic elasticity in hypertension patients.     

Early detection of lesions of dorsal artery of foot in patients with type 2 diabetes mellitus by high-frequency ultrasonography

This study evaluated the value of high-frequency ultrasonograpy for early detection of dorsal artery of foot in patients with type 2 diabetes mellitus （MD）. Eighty subjects including 40 patients with type 2 MD （T2DM group） and 40 healthy volunteers （NC group） were recruited. The intima-media thickness （IMT）, the inner diameter and the perfusion of dorsal artery of foot were measured by using high-frequency ultrasonograpy. Meanwhile, the parameters of vascular elasticity, including stiffness parameter （]3）, pressure-strain elastic modulus （Ep）, arterial compliance （AC）, augment index （AI）, and pulse wave conducting velocity （PWV]3） were detected by means of echo-tracking technique. The results showed that no significant difference was found in the IMT, systolic diameter （Ds）, diastolic diameter （Dd） and peak systolic velocity （PSV） between T2DM and NC groups. Ep and PWVβ were increased, and AC was decreased in T2DM group as compared with those in NC group with the differences being significant （P〈0.05 for all）. There was no significant difference in β and AI between T2DM and NC groups. It was concluded that high-frequency ultra- sonography in combination with echo-tracking technique is sensitive and non-invasive, and can be used for early detection of sclerosis of the lower extremity artery in patients with type 2 MD.     

超声极速成像脉搏波技术评估青中年 2型糖尿病病人颈动脉弹性的价值

目的探讨超声极速成像脉搏波( ufPWV)技术在定量检测青中年 2型糖尿病( T2DM)病人颈动脉弹性的应用价值。方法选择 2019年 9月至 2020年 7月合肥市第二人民医院收治的 77例 18~60岁的青中年 T2DM病人作为病例组,选择同期 18~60岁的来该院健康体检者 77例作为对照组。收集两组病人的一般临床资料、实验室数据、常规超声测量参数及颈动脉弹性指标［收缩期开始时脉搏波传导速度( BS-PWV)和收缩期结束时脉搏波传导速度( ES-PWV)］。按年龄分为青年亚组和中年亚组,分别比较两组间各项指标有无差异,并进一步将病例组的糖化血红蛋白( HbA1c)和内中膜厚度( IMT)分亚组进行分析。结果青年亚组和中年亚组 T2DM病人左、右侧 IMT［(青年:(0.58±0.09)mm、(0.56±0.11)mm;中年:(0.60±0.09)mm、(0.59± 0.10)mm)］,左、右侧 BS-PWV［青年:(5.36±0.82)m/s、(4.61±1.03)m/s;中年:(5.83±1.42)m/s、(4.92±1.22)m/s］,左、右侧 ES-PWV［青年:(6.55±1.50)m/s、(5.64±1.34)m/s,中年:(8.09±2.02)m/s、(7.32±1.98)m/s］和双侧 IMT［青年:(0.57±0.09)mm,中年:(0.60± 0.08)mm］、双侧 BS-PWV［青年:(4.98±0.64)m/s、中年:(5.37±0.98)m/s］、双侧 ES-PWV［青年:(6.09±1.09)m/s、中年:(7.70±1.70) m/s］均高于对照组( P<0.05)。两个年龄组 T2DM病人各自组内 HbA1c增高组与 HbA1c正常组比较,均除左侧 BS-PWV外其余指标差异有统计学意义( P<0.05)。两个年龄组 T2DM病人的 BS-PWV和 ES-PWV在各自组内不同 IMT组间差异有统计学意义(P<0.05)且随着 IMT的增高, BS-PWV和 ES-PWV均有上升的趋势(趋势检验 P<0.05)。结论 ufPWV技术可无创检测青中年     

Noninvasive ultrasound elasticity imaging (UEI) of Crohn's disease: animal model

Inflammation occurs in episodic flares in Crohn's disease, which are part of the waxing and waning course of the disease. Healing between flares allows the intestine to reconstitute its epithelium, but this healing results in the deposition of fibrotic scar tissue as part of the healing process. Repeated cycles of flares and healing often lead to clinically significant fibrosis and stenosis of the intestine. Patients are treated empirically with steroids, with their many side effects, in the hope that they will respond. Many patients would be better treated with surgery if we could identify which patients truly have intestinal fibrosis. Ultrasound elasticity imaging (UEI) offers the potential to radically improve the diagnosis and management of local tissue elastic property, particularly intestinal fibrosis. This method allows complete characterization of local intestine tissue with high spatial resolution. The feasibility of UEI on Crohn's disease is demonstrated by directly applying this technique to an animal model of inflammatory bowel disease (IBD). Five female Lewis rats (150-180g) were prepared with phosphate buffered solution (PBS) as a control group and six were prepared with repeated intrarectal administration of trinitrobenzenesulfonic acid (TNBS) as a disease group. Preliminary strain measurements differentiate the diseased colons from the normal colons (p < 0.0002) and compared well with direct mechanical measurements and histology (p < 0.0005). UEI provides a simple and accurate assessment of local severity of fibrosis. The preliminary results on an animal model also suggest the feasibility of translating this imaging technique directly to human subjects for both diagnosis and monitoring.     

Resonance frequencies and stability of a current-carrying suspended nanobeam in a longitudinal magnetic field

The resonance frequencies and stability of a nanobeam in a longitudinal magnetic field are investigated.To this aim,a three dimensional beam model is uscd in which the small-scale effect is taken into ...     

青年尸眼前囊膜弹性的研究

目的 研究青年人晶状体前囊膜弹性，以例提高白内障摘出和人工晶状体植入术的成功率。方法 测量53人共90只尸眼（平均年龄26.8a)晶状体前囊膜连续环形撕开口的弹性。结果 前囊膜撕开口弹性为1.38-2.74，前囊膜撕开口直径越大，弹性越大；前嗝 膜弹性与年龄无关。结论 本年龄段内（19-40a)前囊膜弹性与撕开口直径呈直线正相关，青壮年期白内障术中前囊膜撕开口直径5.0-5.5mm为宜。     

Dermal fluid translocation is an important determinant of the diurnal variation in human skin thickness

BACKGROUND: Ultrasonography has been used as a non-invasive approach to measure skin thickness. To date there have been no studies on diurnal variations in skin thickness. OBJECTIVES: To evaluate diurnal variations in skin thickness and to compare these with corresponding echogenicity and skin elasticity. METHODS: Measurements by ultrasonography B-mode and by Cutometer SEM 575 were carried out in the morning and in the afternoon on 20 men and 20 women (mean age 30 years) on three areas of the face (forehead, corner of the eye and cheek), the forearm and the upper arm, and the flank, thigh and calf. RESULTS: From the morning to the afternoon, the skin thickness in both sexes significantly decreased on three areas of the face, the forearm and the upper arm, but significantly increased on the thigh and calf. In parallel, the echogenicity significantly increased from the morning to the afternoon on the three areas of the face, the forearm and the upper arm, but decreased significantly on the thigh and calf. Measurements of mechanical properties at four sites demonstrated that from the morning to the afternoon, the major parameters of skin elasticity Ue* and Uf* increased significantly in both sexes on two areas of the face and slightly on the forearm, but decreased significantly on the calf. CONCLUSIONS: The diurnal profiles of skin thickness and skin elasticity in the upper half of the body are the reverse of those in the lower half of the body. These findings suggest that shifts of dermal fluid from the face to the leg by gravity during the day cause the diurnal variation in skin thickness.     

Mechanical model of blebbing in nuclear lamin meshworks

Much of the structural stability of the nucleus comes from meshworks of intermediate filament proteins known as lamins forming the inner layer of the nuclear envelope called the nuclear lamina. These lamin meshworks additionally play a role in gene expression. Abnormalities in nuclear shape are associated with a variety of pathologies, including some forms of cancer and Hutchinson–Gilford Progeria Syndrome, and often include protruding structures termed nuclear blebs. These nuclear blebs are thought to be related to pathological gene expression; however, little is known about how and why blebs form. We have developed a minimal continuum elastic model of a lamin meshwork that we use to investigate which aspects of the meshwork could be responsible for bleb formation. Mammalian lamin meshworks consist of two types of lamin proteins, A type and B type, and it has been reported that nuclear blebs are enriched in A-type lamins. Our model treats each lamin type separately and thus, can assign them different properties. Nuclear blebs have been reported to be located in regions where the fibers in the lamin meshwork have a greater separation, and we find that this greater separation of fibers is an essential characteristic for generating nuclear blebs. The model produces structures with comparable morphologies and distributions of lamin types as real pathological nuclei. Thus, preventing this opening of the meshwork could be a route to prevent bleb formation, which could be used as a potential therapy for the pathologies associated with nuclear blebs.