Respiratory mechanics during mechanical ventilation: a model study on the effects of leak around a tracheal tube

Recently published studies indicate a potential clinical application of PET in head and neck tumors. In the preoperative staging phase, PET enables confirmation of regional lymph node extension and guides nodal neck dissection or systemic treatment. In this phase, a high negative predictive value, near 100%, could make it possible to avoid many negative neck dissections. This is a reliable technique for confirming or excluding the presence of recurrent/residual tumor and for obtaining an early evaluation of chemotherapeutic and radiotherapeutic response. PET imaging in many cases makes it possible to locate and guide histological study of tumors with an unknown primary. PET imaging for these indications is a perfect complementary method for clinical exploration and better than other imaging techniques.     

混酸PEG酯的合成及性能研究

用从大豆油脚水解制得的脂肪酸合成混酸聚乙二醇酯，通过测定酸值的方法确定了最佳反应时间为16h。与油酸聚乙二醇酯相比，混酸聚乙二醇酯具有更优良的乳化性、润湿性，可以替代油酸聚乙二醇酯用于纺织、农药和化妆品工业中。     

铸铁热分析用试样新型激冷剂的实验研究

从冷却曲线上相变段倾角最小原则出发，研究了新型激冷剂的配比与热分析法检测铸铁成分精度的关系，实验结果表明，能使相变段倾角最小的成分配比，也能提高对铸铁成分的热分析和检测精度。     

Inflammatory myofibroblastic tumor in children

The authors presented the cases of two children with inflammatory myofibroblastic (IMF) tumor and reviewed the literature to facilitate the preoperative recognition, delineate the clinical features, and describe the natural history of this entity. The first child had IMF tumor arising from the mesentery of the small intestine. He presented with an abdominal mass associated with severe inflammatory response manifested by fever, impaired growth, thrombocytosis, and microcytic, hypochromic anemia. After surgical resection, his fever resolved and his growth rate and the laboratory abnormalities normalized. Five months after initial diagnosis, the fever, anemia, and thrombocytosis recurred along with two tumors arising from the omentum and the abdominal soft tissue. After the second surgery, he remains free of recurrent disease for 30 months. The second child presented with a lung mass that was radiologically indistinguishable from pulmonary sequestration. After surgical resection, she remains free of recurrent disease for 18 months. IMF tumor should be considered in any solid tumor that occurs in association with a chronic inflammatory response. IMF tumor should also be considered in the differential diagnosis of pulmonary sequestration.     

片状陶瓷材料高低温电性能参数的自动检测

由进口电性能仪配上自制的高温系统，计算机自动采集数据，配置成一套高低温电性参数测定装置，该装置的特点是，升温快，炉体小巧，炉芯可更换盛液氮装置，屏蔽良好，等温区长，温工及参数测量精确可靠。     

Combination oral contraceptives and cardiovascular disease

The abundance of rapid eye movement (REM) sleep in the neonatal mammal and its subsequent decline in the course of development, as well as the dramatic and widespread enhancement of CNS activity during REM sleep, led us to propose that this state plays a functional role in the normative physiological and structural maturation of the brain [54]. When, after 1 week of monocular deprivation (MD), a second week of MD was coupled with behavioral deprivation of REM sleep, the structural alteration in the visual system provoked by MD alone (interlaminar relay cell-size disparity in the lateral geniculate nucleus (LGN) was amplified. With the addition of REM deprivation during MD, the LGN cells connected to the surgically patched eye, which are smaller than normal after MD, became even smaller, whereas the LGN cells receiving input from the seeing eye, which display compensatory hypertrophy after MD, grew even larger. We believe that the interlaminar disparity effect widened because during REM deprivation, the already vision-compromised LGN cells associated with the patched eye also lose the ascending brainstem activation reaching them during the REM state. Loss of the two main sources of 'afference' by these LGN cells permits their seeing-eye LGN counterparts to gain even greater advantage in the competition for synaptic connections in cortex, which is reflected in the relative soma sizes of the LGN relay cells. It is likely that the relatively abundant REM state in early maturation provides symmetric stimulation to all LGN relay cells, irrespective of eye of innervation. The symmetric activation propagated from brainstem to LGN acts to 'buffer' abnormal, asymmetric visual input and, thereby diminishes the extreme, asymmetric structural alteration that results from MD in the absence of REM sleep. We conclude that REM sleep-generated CNS discharge in development has the effect of 'protecting' the CNS against excessive plasticity changes. This is consistent with the possibility that REM sleep plays a role in the genetically programmed processes that direct normative brain development.     

Fetal fast MR imaging: reproducibility, technical quality, and conspicuity of anatomy

PURPOSE: To evaluate the normal appearance of fetal anatomy, the conspicuity of fetal organs, the reproducibility of images, and the limitations to image quality with the use of half-Fourier, single-shot rapid acquisition with relaxation enhancement (RARE) magnetic resonance (MR) imaging. MATERIALS AND METHODS: Fifty-four fetuses of 49 pregnancies underwent MR imaging with the half-Fourier, single-shot RARE technique. Two reviewers attempted to identify 47 organs and anatomic regions in each fetus. Organ or region conspicuity, image quality, and the limitations of image quality were graded. RESULTS: Fetal anatomy was well depicted in fetuses over 20 weeks in gestational age. Fetal imaging was limited by gestational age of 20 weeks or less usually owing to the small size of the organ or region being evaluated and, less frequently, by motion. CONCLUSION: Half-Fourier, single-shot RARE MR imaging provided a detailed and reproducible evaluation of normal fetal anatomy, which can be used as a standard of reference in MR imaging of fetal anomalies.     

Different immunological mechanisms contribute to cartilage destruction in antigen-induced arthritis

Antigen-induced arthritis in guinea pigs was used as a model to investigate the pathogenic mechanisms responsible for cartilage destruction in chronic joint inflammation. The activation of macrophages, their effects on cartilage metabolism, and the development of autoimmunity to cartilage constituents were studied during the progression of arthritis. The results show that in arthritic animals the macrophages are systemically activated, with a peak in the early phase of inflammation. Interleukin 1, produced by the activated cells, suppresses the proteoglycan synthesis in cartilage explants and cultured chondrocytes and increases the proliferation of the cells in vitro. During the progression of arthritis humoral and cell-mediated immune responses to collagen type II and cartilage proteoglycans occur correlating with the severity of arthritis. It is concluded that different immunological mechanisms may be involved in cartilage destruction during antigen-induced arthritis. Mediator-induced metabolic reactions dominate in the early phase, whereas autoimmunity to cartilage might play an essential role in later phases of arthritis.