试验大鼠模型中的线性和大环类钆对比剂的长期排泄

目的观察1年内多次给予含钆对比剂(GBCA)后大鼠脑MRI信号强度(SI)的长期变化过程及脑内钆的存在情况。材料与方法分别给予大鼠线性GBCA(钆双胺、钆喷酸葡胺、钆贝葡胺)和大环GBCA(钆布醇、钆特酸葡甲胺、钆特醇)或生理盐水。

在设计中艺术地生活

《设计》杂志倡导，生活就是设计。对比窗艺廊（Contrasts）认为，设计是人人都能够参与其中的视觉语言。因为这个契合点，在对比窗举办的邵帆个人作品展现场，《设计》第一时间采访了对比窗的创办人林明珠女士和设计师邵帆先生。

啮齿类动物应用钆对比剂后钆在皮肤长期滞留的研究

一些文献提示含钆对比剂（GBCA）与一种罕见但严重的疾病——肾源性系统性纤维化（NSF）有潜在联系。本研究目的是确定大鼠注射GBCA后皮肤组织钆的清除时间。将目前市场应用的7种含钆对比剂以2．5mmol／kg的剂量连续5d注入Han—Wistar大鼠尾静脉中，于最后1次注射后1年内的不同时间点．取皮肤活检应用电感耦合等离子体质谱（ICP—MS）进行钆的浓度测定。皮肤内大部分注射的钆在2个月左右的时间内排除。

An Adaptive Pulse Compression Filter for Ultrasound Contrast Harmonic Imaging

Coded excitation is useful for ultrasound contrast imaging to increase penetration and SNR, and improve the contrast to tissue ratio (CTR). The waveform of bubble response depends greatly on bubble size, the frequency and bandwidth of the excitation chirp signal. This makes the pulse compression filter based on square-law be wrong for bubbles with changing sizes. In this paper, an adaptive pulse compression (APC) filter for the second harmonic of microbubble with varying size distribution is proposed. The APC filter is designed based on the estimated power spectrum of the received bubble harmonic echoes. Theoretical analysis and simulation studies are presented for evaluating performance of the APC filter. For monodisperse bubble, the power improvement factor of the APC filter can be more than 20 dB.

生活用纸消费者感言——关注性价比和环保

因为有两个孩子,我经常清理溢出的食物、水渍、鼻涕等,因此使用了许多生活用纸产品。每年冬季,伴随着易发的感冒和打喷嚏症状,我和家人要使用大量的盒装面巾纸。我们在卧室、客厅和办公室都放了盒装面巾纸。我还喜欢随身携带一包纸巾,在外出时,可以随时随地擦眼泪、污渍和血渍,真的是多功能产品!厨房纸巾堪比“救命稻草”,可以清理溢出的食物,也可在用餐时作为儿童的临时餐巾纸。孩子们会在制作手工的过程中重复使用厨房纸巾和卫生纸的纸卷芯,我们在绘画时会使用大量的厨房纸巾来清理脏东西。圣诞节临近的时候,我通常会购买一些精美的圣诞节主题餐巾纸使用。

Oral Gd-DTPA as a negative gastrointestinal contrast agent in magnetic resonance cholangiopancreatography

Objective: To evaluate the value of oral Gd-DTPA as a negative contrast agent during magnetic resonance cholangiopancreatography (MRCP) to eliminate the high signals of the gastrointestinal tract. Methods: To select the optimal concentration of oral Gd-DTPA for MRCP, a phantom study was performed followed by clinical trial in 15 cases undergoing MRCP before and after oral Gd-DTPA (in a total volume of 250 ml 1∶5 diluted Gd-DTPA, 1.488 g/L). MRCP images were acquired using two-dimensional single slice fast spin-echo (SSTSE) sequence and half-Fourier acquisition single slice fast spin-echo (HASTE) sequence. Results: The phantom study showed that the 1∶5 diluted oral Gd-DTPA was best in decreasing the signal intensity both in T2-weighted imaging (59.5%) and in HASTE sequence (82.45%). The high signal intensity of the stomach and intestinal fluid was completely suppressed in all the cases. The depictions of the common bile duct and pancreatic duct were markedly improved by using the oral contrast agent (P<0.05). Conclusion: Oral Gd-DTPA is effective and safe for eliminating the high signal of the gastrointestinal tract to improve the depiction of the biliary system by MRCP.

Simulation of Desert-Scrub Growth: A Forcing to Warmer and More Pluvial Climate

Desert-fringe vegetation growing over bright, sandy soils reduces the surface albedo from above 0.4 to well below 0.3. Called desert-scrub, these shrubs form a predominantly vertical clumps protruding from the soil-level, thereby significantly increasing the coefficient of turbulent heat transfer from the surface. The impact on global and desert-belt climate of changes in these two surface characteristics was simulated by a multi-layer energy balance tnodel. Evaluated only as a forcing to a further climatic change (that is, without accounting for any possible feedbacks) the results are: if vegetation (such as apparently existed under the warmer climate of 6,000 BP ) grows over large areas in the arid, currently bare-soil regions, the annual Northern Hemisphere surface temperature increases by 0.7t (by 0.6'C in July ), the surface temperature over land in the 20-30°N zone increases by 0.9℃ in both the annual and the July means, and the land-ocean annual temperature contrast in this zone increases by 0.25℃(0.2° in July). These results represent the combined influence of the reduction in the surface albedo and of the increase in the coefficient of turbulent heat transfer. In the desert-belt zones, the increase in the transfer coefficient sharply reduces the land temperature and the land-ocean temperature contrast from the values produced by the albedo change alone. This reduction must be attributed to the increased land-to-ocean circulation (which our model does not evaluate explicitly). Considering that a stronger circulation (resulting from land-ocean temperature contrast) generally forces a higher rainfall, the vegetation which emerged in the arid regions during the post-glacial optimum should be considered a significant positive feedback towards a still warmer, and also a more pluvial, climate. Our study may have implications for the 21st century, if the global warming expected from the enhanced greenhouse effects is accompanied by increased precipitation over the continents.

EFFECTS OF VARIOUS VASOACTIVE AGENTS ON TUMOR BLOOD FLOW IN RAT

Effects of angiotensin Ⅱ and other six vasoactive agents on tissue blood flow of Yoahida rat ascites hepatoma AH109A and normal liver were measured by the hydrogen clearance method. The mean blood flow in the tumor peripheral part under normal tension was 11. 9±8. 2ml/ min/100g tissue and was not influenced by tumor size. Tumor blood flow was more significantly increased in infusion angiotensin Ⅱthan 0.5mg/ ml methoxamine, however, normal liver blood flow of tumor-bearing rats was unchanged in contrast to an Increase seen in the tumor. A pronounced reduction of tumor blood flow was found after administration of epinephrine, norepinephrin and ethylphenylephrine. In addition, metaraminol and phenyleprine as well as 1. 0 and 2. 5mg/ ml methoxamine were not found to significantly change blood flow of the tumor.

ENZYME-LINKED IMMUNOSORBENT ASSAY OF HUMAN PLACENTA TYPE GLUTATHIONE S-TRANSFERASE AND ITS APPLICATION IN THE DIAGNOSIS OF HEPATOCARCINOMA

GST-π was purified from human placenta and its antiserum was raised in rabbits. The antibody IgC was purified and degraded into Fab' fragment which was conjugated with horseradish peroxidase (HRP) using N-succinimidyl-4-(N-maleimido-methyl) cyclo-hexane-1-carboxylate (SMCC) as crosslinking reagent to produce Fab'-HRP conjugate. A sandwich ELISA was established for the microquantitative determination of GST-π. The sensitivity was 11 pg/tube, which was far more sensitive than the radioimmunoassay so far reported. Using this method, the serum GST-π of 41 cases normal adult was found to be 1.06±0.94 ng/ml. The upper limit of the normal value was 2.6 ng/ml. In 30 cases of primary hepatocarcinoma, the level of serum GST-π was 24.4± 17.4 ng/ml, which was 23 times higher than the normal average value (P<0.01). The positive rate was 90%. In contrast, serum GST-π in 25 cases of chronic hepatitis was determined to be 1.74±1.16 ng/ml, which was not significantly different from the normal value (P>0.05). The pseudo-positive rate was 12.0%.

Mice aorta loop grafting: A new model which separate vascular rejection and neointimal formation in chronic rejection

Objective: To study the cause and mechanism of transplantation vasculopathy which characterized by accelerated graft arteriosclerosis (AGA), we established a mouse aorta graft model. Methods: A segment of thoracic aortas of B10.A (2R) mice were transplanted to C57BL/10 mice abdominal aorta by end to side anastomoses. The different time point collected grafts were analyzed by morphological, histochemical and electro microscopic methods. Results: Rejection was manifested as a concentric progressive destruction of the smooth muscle cells. In contrast, the endothelial inflammation and subsequent neointimal proliferation characteristic of AGA was localized to the regions of turbulent flow, i.e. the junction of the graft with the recipient aorta. Conclusion: This model separates the processes of rejection and neointimal formation which usually manifested together in the lesion of AGA, elucidate that different mechanisms control vascular rejection and neointimal formation in chronic rejection.

GENE ENGINEERING EB VIRUS MEMBRANE ANTIGEN IN DETECTION OF MA-IgA ANTIBODY(COMPARISON WITH VCA-IgA AND EA-IgA ANTIBODIES)

With gene engineering EB virus membrane antigen as the diagnostic antigen, indirect immunofluo-rescence (IF) assay was used to detect IgA antibody against EB virus membrane antigen (MA-IgA) in sera from 202 nasopharyngeal carcinoma (NPC) patients and 315 controls (normal and patients with other tumors). MA-IgA antibody was positive in 96.8% of the pretreatment NPC patients with a GMT of 1:36.3. MA-IgA detection by this method was more sensitive than EA-IgA detection by IE. In contrast, patients with tumors other than NPC were negative for MA-IgA antibody. 9.1% of VCA-IgA positive persons were MA-IgA positive with a GMT of less than 1:5. No MA-IgA positive was found in VCA-IgA negatives. The results indicated that this method was relatively specific. In the treatment group, the positive rate and GMT of MA-IgA antibody declined with increase in survival time and the decline was faster than VCA-IgA. When recurrence or distant metastasis developed, similar to VCA-IgA and EA-IgA antibodies, the positive rate and GMT of MA-IgA antibody increased to its pretreatment level. Therefore, MA-IgA detection might be valuable in the early diagnosis and monitor of NPC.

Study on biocompatibility of PDLLA/HA/DBM with co-cultured human osteoblasts in vitro

Objective: To evaluate the osteocompatibility of D, L-polylactic/hydroxyapatite/decalcifying bone matrix (PDLLA/HA/DBM), and compare with PDLLA and DBM. Methods: Human primary osteoblasts isolated from the femoral head of patients were inoculated onto PDLLA/HA/DBM, PLA and DBM respectively. The proliferation rate and collagen Ⅰ expression were detected. The interface between biomaterial and osteoblasts was investigated with phase contrast microscopy and electron scanning microscopy. Results: Best proliferation rate was observed with the PDLLA/HA/DBM and followed by DBM and PLA, suggesting that PDLLA/HA/DBM satisfying most requirements for the cultivation of human osteoblasts. Scanning electron microscopy showed the morphology of osteoblasts was correlated with the proliferation data. The cells, well spread and flattened, were attached closely on the surface of biomaterial with an arched structure and had normal morphology. The extracellular collagenous matrixs covered the surface of biomaterial and packed the granules of biomaterial. Conclusion: PDLLA/HA/DBM can form osteointerface early and have a good biocompability.

Management of extensive closed internal degloving injury in lower limb and peripelvis

In contrast to open degloving injury, extensive closed internal degloving injury (CIDI) is rare, especialy followed by deep injury with bone-articular and neurovascular complications after initial trauma.1-3 Clinically, it 05- be misdiagnosed or mismanaged leading to delayed full-thickness necrosis of the avulsed skin flap and development of wound sepsis, 3 even limbs disability.4 A number of reports have advocated several means for treatment of CIDI1,3,5,6 but they are not ideal.1,6,7 Since 1987 we have treated 132 degloving injuries, 18 (13.6%) of whom were CIDI in the peripelvis and lower limbs. According to the severity of CIDI, it has been managed by replantation of defatted full-thickness degloved skin with refined techniques as salvage procedures for the avulsed skin, and defect coverage with several myocutaneous flaps for denuded wound of specialized areas. Our purpose is to stress the importance of simultaneous management of both CIDI and deep injury and proper options of resurface procedures to provide better appearance and function of limbs.

A NEW PROBE OF APPLICATION OF SILICON ISOTOPIC δ^(30) Si IN SILICEOUS ROCKS TO SEDIMENTARY FACIES ANALYSIS

The application of isotopic data of carbon (δ 13C), oxygen (δ18O) and sulphur (δ 34S) to the sedimentary facies analysis and environmental study is well known. In contrast, a study on silicon isotopes is rare, although silicon contains major contents of rock-made components in sedimentary rocks. Silicon has three kinds of stable isotooes i. e.

A modified moire interferometer for three-dimensional displacement measurement

This paper presents a new optical interferometric system, MMI-T/G, composed of a modified four-beam moire interferometer and a Twyman/Green interferometer. The MMI-T/G system can measure three-dimensional displacement fringe patterns with a single loading on the specimen, and the in-plane and out-of-plane displacement fields can be measured independently and defined clearly. The optical setup has the advantages of structural novelty, flexibility, and high fringe contrast. Moreover, the in-plane displacement sensitivity is twice of that of the normal moire interferometer. The measuring techniques to obtain the fringe patterns and displacement fields using the MMI-T/G system are described. The experimental results of thermal displacement of an electronic device are shown.

Experimental study on the adhesion, migration and three-dimensional growth of Schwann cells on absorbable biological materials

OBJECTIVE: To study the adhesion, migration and three-dimentional growth of Schwann cells on PLA (polylactic acid) nonspinning fibre cloth and polyglycolic/polylactic acid (PLGA) fibres. METHODS: Schwann cells/ECM gel solution and PLA nonspinning fibre cloth and PLGA fibres pretreated by collagen, polylysine and ECM were co-cultured. Then the migration and three-dimensional growth of Schwann cells on the fibres were observed under phase contrast microscope and laser scanning confocal microscope. RESULTS: Schwann cell/ECM solution was compounded with PLA nonspinning fibre cloth. With formation of gel, most Schwann cells resided in the fibre net holes, and adhered to the fibres to form a multiplayer-arranged Schwann cell column like Bungner band. Schwann cells could adhere to PLGA fibres and grew and migrated along the fibres. ECM gel could significantly increase the adhering and migrating cell number. CONCLUSIONS: ECM gel can facilitate the adhesion, growth and migration of Schwann cells on the seteroframe. It is a good integrating material for tissue engineering bioartificial nerve.

Average modulation transfer function of line-array fiber-optic image bundles

The image quality evaluation in fiber-optic image bundles was addressed by the modulation transfer function (MTF). With the definition of the contrast transfer function (CTF), the MTF model of line-array fiber-optic image bundles was established and analyzed numerically. The average MTF was carefully evaluated by considering the influence of phase match on the MTF between input pattern and fiber-optic image bundles. In this paper, the average MTF is mean arithmetical value on the MTFs of eight different phases. The results show that, for certain fiber diameter and spatial frequency, the relationship between the core diameter and the average MTF is inverse proportion; for certain fiber cladding thickness, the relationship between the core diameter and the average MTF is also inverse proportion. And at Nyquist frequencv. the MTF value is near 0.5.

THE FUNCTIONAL ROLE OF 23 kD AND 24 kD POLYPEPTIDES OF THYLAKOID IN Mg^(2+)-INDUCED CHANGE OF EXCITATION ENERGY DISTRIBUTION BETWEEN TWO PHOTOSYSTEMS IN THE CHLOROPLASTS FROM Codium fragile

In contrast to the chloroplasts from higher plants, Mg^(2+)-induced PS--Ⅱ fluorescence inten-sity increase does not relate to Mg^(2+)-induced surface charge density decrease of thylakoidin the chloroplasts from Codium fragile. Tbe extraction of the green alga chloroplasts withCa^(2+) to remove the 30--31kD polypeptide (Q_B protein) on the thylakoid surface does notaffect the above Mg^(2+)-induced phenomena. If the Ca^(2+)-treated chloroplasts are further di-gested by trypsin to remove the 23kD and 24kD polypeptides on the membrane surface,the Mg^(2+)-induced fluorescence effect will completely disappear whereas the property ofMg^(2+)-induced surface charge density changes remains unchanged. These results not onlyshow that the 23kDa and 24kDa polypeptides on the thylakoid surface are the specific act-ing sites of the cation that induce Chla fluorescence change, but also demonstrate that thecation-induced change of excitation energy distribution between two photosystems is not con-trolled by the electrostatic property of thylakoid surface in the chloroplasts of Codiumfragile.

Depression of Calcium Transients After Exposure to High K^+ Solution in Li^+-loaded Frog Twitch Muscle Fibres and Its Reversal by Exogenous Myo-inositol

Using Arsenazo Ⅲ as a myoplasmic calcium indicator, we have studied the calcium transients evoked by voltage-clamp depolarizing pulses in frog twitch muscle fibres which had been temporarily depolarized by 80 mmol/LK^+ in the absence or presence of myoplasmic Li^+. After the high K^+ exposure, for either a short (15 rain) or long(1 h) time, the post-K^+ calcium transients could gradually be restored to the level of the pre-K^+ ones, if the fibres were not loaded with Li^+.In contrast, the post-K^+ calcium transients of Li^+-loaded fibres could not fully recover,and were depressed in a Li^+ concentration-dependent manner.The mean amplitude of the post-K^+ responses recorded more than 3.5 h after 15 min high K^+ exposure was reduced to 56% of pre-K^+ control in the fibres which had been loaded with Li^+ in 20 mmol/L Li^+ Ringer's solution.This depression could be prevented or partially reversed by exogenous myo-inositol.More depression could be induced by 1 h high K^+ exposure, but the presence of exogenous myo-inositol could not clearly prevent the post-K^+ calcium transients from reduction.Assuming that high K^+ exposure caused a depletion of myo-inositol and probably other changes in the metabolism of inositol phospholipids in Li^+ loaded fibres,we conclude that some metabolites of phosphoinositides may play modulation roles in excitation-contraction coupling in frog twitch muscle fibres.

CsA down regulates IFN-γ gene transcription after liver transplantation by inhibiting NF-κB activity

Objective To investigate the relationship between NF-κB activity and IFN-γ gene expression, as well as the histopathological changes following liver transplants, both with and without cyclosporin A (CsA) treatment.Methods Sixty male Wistar and Thirty male SD rats were subjected to orthotopic liver transplants. Fourty-five of the Wistar rats were used as recipients, and were divided into 3 groups: group Ⅰ , syngeneic control (Wistar-to-Wistar); group Ⅱ , acute rejection (SD-to-Wistar); and group Ⅲ: acute rejection treated with cyclosporin A by intramuscular injection (SD-to-Wistar + CSA). After the liver transplants, electrophoretic gel mobility shift assay was used to analyze NF-κB activity in the splenocytes of recipient rats, and RT-PCR was used to measure IFN-γ gene expression in grafted liver specimens. In addition, histopathological examinations were performed to assess the severity of acute liver rejection.Results In group Ⅰ , low levels of NF-KB activity were only detectable on day 5 and 7 post-transplant, and only weak IFN-γ mRNA expression was observed at all time points. By contrast, both high NF-κB activity and high expression levels of IFN-γ mRNA were detected at all time points in group Ⅱ. In group Ⅲ, NF-κB activity and IFN-γ mRNA expression were significantly inhibited, as compared to group Ⅱ (P < 0. 05). A good correlation was found between NF-κB activity and IFN-γ mRNA expression (r = 0.815) . In addition, NF-κB activity and IFN-γ mRNA expression mirrored histopathological changes in all three experimental groups.Conclusions Changes in IFN-γ mRNA expression levels after liver transplantation are at least partially due to changes in levels of NF-κB activity. CsA appears to downregulate NF-κB activity, thus inhibiting IFN-γ gene transcription. Blocking the NF-κB mediated transcription pathway may be of benefit in preventing liver transplant rejection.