水煤气净化系统氨积累处理方法

对水煤气净化系统氨积累成因进行分析,由于流体流动边界层的存在,氨与部分冷凝水在换热器管程内壁反应形成盐溶液并在管程内冷却结晶,从而造成铵盐结晶.从能量利用和水的平衡进行分析,提出改进措施,为合成氨装置技改提供参考.     

Effects of race, sex, and socioeconomic status upon cardiovascular stress responsivity and recovery in youth

In rat brain, expression of the gap junction protein connexin30 increased during the first 3 weeks after birth and reached its maximum after 4 weeks, as shown by analysis with specific connexin30 antibodies. This contrasts with the prenatal onset of connexin43 expression. On cryosections of rat brain, connexin30 immunoreactivity was found near blood vessels and in ependymal as well as in leptomeningeal cells. Expression in the neuropil was first noticed 3 weeks after birth, showing the same spatial pattern of immunoreactivity as connexin43. This late onset of connexin30 expression in astrocytes was also seen in long-term glial cell cultures, where connexin30 was coexpressed with the astrocytic marker proteins S-100beta and glial fibrillary acid protein. In acute brain slices, connexin30 immunofluorescent signals were detected on processes of functionally identified astrocytes. Thus, our results show that connexin30 is expressed in three different cell types of the rodent brain. The late onset of connexin30 expression in astrocytes suggests that this gap junctional protein fulfills a role in intercellular communication among mature astrocytes.     

Topography following keratoplasty in cats is not representative of that in humans

The excurrent duct system of the rat submandibular gland consists of a number of distinct segments. Using the direction of salivary flow as a reference point, these segments are, in order, intercalated duct, granular convoluted tubule, striated duct, excretory duct, main excretory duct (MED), and salivary bladder (which is an expanded portion of the MED). Because these ducts (with the exception of the MED and the salivary bladder) are encased in secretory endpieces, they are difficult to locate and to observe by scanning electron microscopy. A simple method has been devised to rid the gland of these obscuring endpieces so that the detailed architecture of the duct system can be examined. Rat submandibular glands were fixed initially by vascular perfusion with half-strength Karnovsky's fixative. The connective tissue capsule was removed from extirpated glands and the glands remained in fixative for varying lengths of time. For our purposes, a 30-minute immersion in the aldehyde mixture was optimum. After the sublingual gland was removed, the submandibular gland was softly struck with forceps having rounded tips, then shaken in fixative or buffer. The tissue that remained was postfixed in osmium tetroxide. This method results in the complete divestment of nonductular parenchyma from the rat submandibular gland, leaving the duct system clean and ready for microscopic examination.     

Molecular characterization of Cyclospora-like organisms from baboons

Cyclospora organisms are intestinal pathogens of humans that are increasingly recognized in many parts of the world; yet, the reservoirs and host range remain poorly defined. Analysis of 18S ribosomal DNA (rDNA) suggests that the human-associated Cyclospora species (Cyc-hu) is most closely related to the Eimeria species, which are host species-specific. Recently, oocysts identical to those of Cyc-hu were detected in baboon fecal specimens from Tanzania. The 18S rDNA from 3 of these baboon-associated oocyst specimens was amplified and sequenced. Phylogenetic analysis indicated that these baboon-associated Cyclospora-like organisms (Cyc-bab) are nearly identical to each other and are distinct from Cyc-hu (1.6%-1.7% dissimilar); however, these Cyc-bab organisms are the closest known relatives of Cyc-hu. Together, these primate-associated cyclosporans constitute a coherent clade within the diverse group of Eimeria species. These findings raise important questions about the evolutionary relationships of the eimeriids and Cyc-hu host range and should lead to improved polymerase chain reaction-based diagnostics.     

Protein replacement by receptor-mediated endocytosis corrects the sensitivity of Fanconi anemia group C cells to mitomycin C

Current methods for direct gene transfer into hematopoietic cells are inefficient. Here we show that functional complementation of Fanconi anemia (FA) group C cells by protein replacement can be as efficacious as by transfection with wild-type FAC cDNA. We expressed a chimeric protein (called His-ILFAC) consisting of the mature coding portion of gibbon interleukin-3 (IL-3) and full-length FAC in Escherichia coli. The purified bacterial protein is internalized by hematopoietic cells via IL-3 receptors. The intracellular half-life of His-ILFAC is approximately 60 minutes, which is comparable to that of the transgene-encoded FAC protein. In this cell-culture model His-ILFAC completely corrects the sensitivity of FA group C cells to mitomycin C, but it has no effect on FA cells that belong to complementation groups A and B. We suggest that receptor-mediated endocytosis of cytokine-fusion proteins may be of general use to deliver macromolecules into hematopoietic progenitor cells.     

Cystic renal cell carcinoma is cured by resection: a study of 24 cases with long-term followup

PURPOSE: The true incidence and biological behavior of cystic renal cell carcinoma are not known. To our knowledge we present the largest series of patients with cystic renal cell carcinoma with long-term followup. MATERIALS AND METHODS: We reviewed the Mayo Clinic surgical pathology files of renal cell cancer cases with a cystic component resected from 1969 to 1997, and arbitrarily chose 75% tumor involvement by cysts as a cutoff for inclusion in the study. RESULTS: We identified 24 cases of clear cell renal cell carcinoma with 75% or greater involvement by cysts comprising 0.79% of 3,047 renal cell cancer cases resected at our institution between 1969 and 1997. Mean patient age was 62.7 years (range 40 to 83). A total of 11 patients (46%) underwent radical nephrectomy, 4 (17%) simple nephrectomy, 3 (12%) partial nephrectomy and 6 (25%) tumor enucleation. Mean tumor involvement by cysts was 84% (range 75 to 95) and in 11 cases (46%) involvement was 90% or greater. Cancer stage was T1 in 20 patients (83%), T2 in 1 (4.4%) and T3a in 4 (12.5%). Cancers were diploid in all but 1 case. Mean followup was 77.6 months (range 8 to 428, median 51). A total of 22 patients (92%) had no evidence of cancer and 2 died of intercurrent disease. CONCLUSIONS: Our results indicate that cystic renal cell carcinoma is uncommon and usually cured by resection, regardless of size, stage or number of cysts. These patients may benefit from nephron sparing surgery, such as partial nephrectomy.     

司帕沙星与洛美沙星临床抗感染作用的比较

目的 比较司帕沙星(SPLX)与洛美沙星(LMLX)的临床抗感染作用。方法 将24例呼吸道和泌尿道等感染患者随机分为SPLX和LMLX两组。SPLX组口服剂量为200~300mg,每日1次;LMLX组口服剂量为200~400mg,每日2次。临床疗效按痊愈、显效、进步和无效四级标准判定。痊愈和显效合计为有效。结果 SPLX组的总用药量显著少于LMLX组,但痊愈率和有效率略高于LMLX组。受试患者的细菌分离率为91.7%,在停药第11天两组的细菌清除率为81.8%和75.0%。两组均未观察到药物不良反应。结论 SPLX为治疗细菌性感染的安全有效的氟喹诺酮类药物,其效应/剂量比要高于洛美沙星。     

85例Stanford B型主动脉夹层腔内修复治疗体会

【摘要】 目的 探讨胸主动脉腔内修复术（TEVAR）治疗Stanford B型主动脉夹层（AD）方法与疗效。方法 回顾性分析2010年1月至2016年4月采用TEVAR治疗的85例 Stanford B型AD患者临床资料。85例患者均常规行左肱动脉穿刺,右侧股动脉直切口,升主动脉DSA造影明确AD破口位置、真假腔及与重要器官血管开口位置关系;置入覆膜血管内支架,封堵原发破口,升主动脉造影复查观察近端破口封闭情况及主动脉弓部分支血管、真假腔血流变化情况。结果 84例患者TEVAR手术成功,成功率100%;1例术前麻醉过程中突发AD破裂死亡。9例部分覆盖左锁骨下动脉,1例左锁骨下动脉“烟囱”支架完全封闭左颈总动脉和左锁骨下动脉,2例行无名动脉至左颈总动脉和左锁骨下动脉转流。Ⅰ型内漏2例,无住院期间死亡。术后随访3个月至3年,患者均存活,远端再发新破口2例。结论 TEVAR术治疗Stanford B型AD安全有效,严格把握手术指征、术中精细操作及加强术后院外管理是手术成功、提高远期生存率关键。

     

EFFECT OF MICROSTRUCTURE OF ALUMINIDE COATING ON HIGH-CYCLE FATIGUE PERFORMANCE OF COATING-SUPERALLOY SYSTEM

The high-cycle fatigue performance of different microstructures of aluminide coating-superalloy system has been studied at 900℃.The single phase coating of coarse equiaxialgrain NiAI(β)has unfavorable eJfect onJatigue life of the coating-superalloy.The fatigue lifemay shorten if the coating of NiAl(β)was an enrichment of coarse refractory metal grains.While an improvement can be made by dispersing numerous secondary phase particles such asextreme.fine γ′,quasi-σ-phase and others.