Search

High energy backscattered electron signals have been measured from 1‐, 3‐, and 10‐μm‐wide gold alignment marks on silicon and gallium arsenide substrates as a function of electron‐beam energy (5–30 keV) and gold film thicknesses (650–10 000 A) using an annular silicon‐diode detector. Thin films of both silicon dioxide (3500 A) and polymethyl methacrylate (5200 A) on gold alignment marks (2600 A) on silicon reduced the original signal contrast at 30‐keV incident‐beam energy by only 16% (10% and 6%, respectively) and degraded the original edge acuity by only about a factor of two. Signal contrast maxima for gold on silicon and gold on gallium arsenide were found to be 1.64 and 0.86, respectively, while silicon and silicon dioxide steps (∠4000 A) produced no more than 0.08 and 0.04 contrast, respectively. The gold on silicon results are presented with the full realization of the general processing incompatibility of gold on silicon devices and circuits at high temperatures. These results are applicable to ot...

A hybrid electron‐beam pattern generation technique is described which utilizes both digital point‐by‐point high resolution pattern definition and an analog ramp low resolution pattern fill‐in. The analog ramp endpoints are set by the digital‐to‐analog converters and are thereby self‐registered to the digital point‐by‐point exposure. This dual approach to pattern exposure allows tradeoffs to be made in the performance required of the individual components which make up the pattern generator. Examples of these tradeoffs are discussed. An overall system throughput model was developed and applied to a specific system based on this hybrid pattern generator. The results of applying this model to the 0.1–1.0‐μm‐linewidth range shows that throughput is strongly influenced by line broadening effects such as electron scattering and processing in the 0.4–1.0‐μm‐line resolution range and that alignment times (mechanical stage and electron beam) become dominant in the 0.4–1.0‐μm range.

Previous studies showed that pulmonary pathological changes after hemorrhagic shock are similar to those after continuous (2 hours) serotonin infusion. Both conditions produce congestive atelectasis, interstitial and intra-alveolar edema and hemorrhage, and red cell aggregation. Studies in 25 dogs compared pulmonary hemodynamics during 2 hours of hemorrhagic hypotension (40 mm. Hg) with methysergide (serotonin antagonist), without methysergide, and with serotonin (75 mcg. per kilogram per minute) alone. During serotonin infusion in normovolemia, both pulmonary artery (PA) and pulmonary vein wedge (PVW) pressure rose. The pulmonary arteriolar and small pulmonary venous (SPV) constriction were statistically and physiologically significant. Pretreatment with methysergide prior to hypovolemia prevented the SPV pressure rise. Lung changes, grossly, microscopically, and by cinemicroscopy, were greatly reduced by administration of methysergide. These results suggest that serotonin—possibly released by the hypoxic intestine, hypoxic brain, or unstable platelets—plays a significant role in the pulmonary changes secondary to hypovolemic hypotension.

Pulmonary and systemic hemodynamics and microcirculatory changes were studied following pulmonary embolism with fresh blood clot. Sudden death was related to massive obstruction. Because denervation of the lung by reimplantation did not alter the acute or progressive hemodynamic changes, neural reflexes were ruled out as an important factor. Serotonin infusions produced the same changes as clot emboli. Both could be ameliorated by reserpine pretreatment, which reduced platelet serotonin content, and by massive doses of heparin, which acts as an antiserotonin and also prevents further platelet aggregation and rupture. Clot infusion into the proximally occluded right pulmonary artery (PA) produced severe changes in the left pulmonary vascular bed and clearly demonstrated that humoral effects occur over and above any mechanical effects of emboli.

A clinicopathologic analysis of 92 pilomatrixomas in 84 children was made. The diagnosis is seldom made clinically, since the lesions are not distinct and are referred to most often as some variety of cyst. The common locations are the face, neck, and arms. The lesion is benign and is cured by excision. In our patients the diagnosis was always established by pathologic study. There are similarities between pilomatrixoma and pilar structures. The tumor probably originates from a primitive cell of the primary epithelial germ and differentiates toward hair-matrix cells. The name "pilomatrixoma" is acceptable, since it conveys the histogenesis of the lesion and avoids the word "epithelioma," which generally indicates a malignant neoplasm and should not be used for this benign tumor.

Thirty-one patients with paraesophageal hernia were studied, and their treacherous clinical course and complications are emphasized. Ten patients had acute upper gastrointestinal bleeding, 9 had obstruction, and 2 had perforation. Primary repair was done for 28 patients. Two esophagogastric resections were undertaken for irreversible ischemia and perforation. One patient had closure of the perforation and hernia repair. There were 2 operative deaths, both of which were related to complications of this disease (obstruction, perforation, and mediastinitis). Paraesophageal hernia must be repaired promptly to alleviate symptoms and to prevent serious complications.

A small, dedicated computer has been interfaced to a scanning electron microscope (SEM) for the purpose of generating, registering, and fabricating microelectronic device and circuit patterns with submicron dimensions. A preliminary registration accuracy of ±0.1 µm over a (950-µm)2pattern field has been demonstrated.

Bei der Einwirkung von POCl3 auf wasserfreies MgBr2 bei Raumtemperatur im Molverhaltnis ≥ 2:1 entstehen die Additionsverbindungen MgBr2 · 2 POCl3 bzw. MgBr2 · 3 POCl3. Die Anwendung eines groseren POCl3-uberschusses bewirkt gleichzeitigen Halogenaustausch, so das die Zusammensetzung des 3:1-Addukts dann der Formel MgBr2−nCln · 3 POCl3 (n ≤ 2) entspricht. Die Anlagerung erfolgt uber den Sauerstoff des POCl3 als Donatoratom, wie aus der Erniedrigung der P=O-Valenzfrequenz in den Addukten um etwa 30 cm−1 hervorgeht. Beim Erhitzen unter 0,01 Torr findet bereits unterhalb von 100·C eine weitgehende Spaltung in die Komponenten statt, wobei neben POCl3 infolge teilweisen Halogenaustauschs auch geringere Mengen POCl2Br und POClBr2 entstehen. Die Addukte MgBr2 · 2 POCl3 und MgBr2 · 3 POCl3 sind auch aus POCl3 und MgBr2 · 3 (C2H5)2O in atherischer Losung darstellbar. Dagegen bildet PSCl3 unter vergleichbaren Bedingungen mit MgBr2 kein entsprechendes Addukt. Gegenuber MgBr2 als Akzeptor ergibt sich daraus die relative Donatorstarke POCl3 ≥ (C2H5)2O ≥ PSCl3. The addition compounds MgBr2 · 2 POCl3 and MgBr2 · 3 POCl3 arise from the interaction of POCl3 with MgBr2 at room temperature depending on the molar ratio (≥ 2:1) of the reactants. Application of a larger excess of POCl3 favours halogen exchange, the 3:1 adduct then corresponding to the formula MgBr2−nCln · 3 POCl3 (n ≤ 2). Addition occurs through the oxygen atom of POCl3 as donor atom as is concluded from the decrease of approximately 30 cm−1 in the PO valence frequency of the adducts. Thermal decomposition occurs at a pressure of 0.01 Torr and temperatures below 100·C yielding POCl3 and smaller quantities of POCl2Br and POClBr2 due to partial halogen exchange. The adducts MgBr2 · 2 POCl3 and MgBr2 · 3 POCl3 are also formed from POCl3 and MgBr2 · 3 (C2H5)2O in ether solution. PSCl3 does not form any corresponding adduct with MgBr2 under similar conditions. With MgBr2 as acceptor, the relative order of donor strengths POCl3 ≥ (C2H5)2O ≥ PSCl3 has been established.

A computer-controlled electron beam microfabrication system has been used to fabricate complex, high-frequency acoustic surface wave devices. System hardware and software, fabrication process, and results are described.

Amyloidosis, both human and experimental, is allied with a multiplicity of predisposing factors. This study was designed to determine whether the presence of one such factor, rheumatoid arthritis, would enhance the tendency for amyloid accumulation in aged persons. With the use of sensitive histologic methods, the autopsy prevalence of amyloidosis in 47 patients with documented severe rheumatoid arthritis was compared to that in 47 nonrheumatoid subjects appropriately matched for sex and age. Contrary to expectations, the frequency and, with one exception, the distribution and amount of amyloid deposition were identical. Only one rheumatoid patient exhibited "secondary" amyloidosis. In this study, the rheumatoid patients exhibited an unexpectedly high frequency of gallstones and relatively low frequency of cancer in comparison to the control group.

A case of benign clear cell tumor of lung is presented. The nature and characteristic histologic features of this tumor are reviewed.

Summary form only given. A computer-controlled electron beam microfabrication system was used to fabricate a GaAs Schottky barrier field effect transistor with a 0.5 μm gate length. This result represents the first time a 0.5 μm gate microwave device has been fabricated by electron beam techniques. The fabrication process described in the paper is a viable method to make devices with submicron gates.

Two groups of rats bearing a transplanted glioma were given methylprednisolone acetate on the tenth, 13th, and 19th days postimplantation. Group 1 animals and half of the group 2 animals were killed on day 21; the remaining group 2 animals were allowed to die from their tumor. Average treated tumor wet weights were 36.25 mg (group 1) and 34.1 mg (group 2), those untreated were 157.5 mg (group 1) and 113 mg (group 2). Group 2 control animals survived an average of 28.7 days, group 2 treated animals an average of 37.4 days. Water content and electrolyte levels in surrounding brain indicated a concomitant antiedema effect. From these data, methylprednisolone appears to be effective against primary brain tumors.

Objective: To investigate effect of body mass index (BMI) on survival and technique failure in patients undergoing peritoneal dialysis (PD). Methods: In this retrospective study three hundred ninety-two consecutive patients undergoing peritoneal dialysis from September 1995 to January 2013 were included. Median PD duration was 53 (range: 4-189) months. Clinical outcomes were mortality and technique failure. Technique failure was defined as transfer to hemodialysis (HD) due to peritonitis, ultrafiltration failure, inadequate dialysis, exit-site and/or tunnel infection, and mechanical problems. Deaths within 3 months after transferring to HD were accepted as PD-related mortalities. The patient and technique survival rates were estimated using the Kaplan-Meier method. Mortality risks were analyzed using the multivariate Cox regression model in which we included (in a backward-wald manner) all the significant variables from the univariate analysis. Results: There were 164 (41.8%) deaths. Forty-six (11.7%) patients underwent renal transplantation whereas 132 (33.7%) patients were transferred to HD. The multivariate Cox regression analysis found that the patient survival rates were significantly associated with age, BMI, baseline serum creatinine and albumin levels, and total Kt/Vurea. All variables as potential risk factors for the patient survival were also assessed for technique survival in univariate analysis and technique survival rates were significantly associated only with BMI (p: 0.015). Conclusion: BMI was associated with unfavorable patient survival in PD patients.