Microwave low-noise AlGaAs/InGaAs HBT's with p+-regrownbase contacts

This paper reports low-noise AlGaAs/InGaAs heterojunction bipolar transistors (HBT's) with p⁺-regrown base contacts. To reduce the thermal and shot noises, we have reduced R_B by using a p ⁺-regrown base contact and have reduced τ_B by using a compositionally-graded thin base layer. As a result, F_min values of 0.9, 1.1, 1.2, and 1.6 dB were obtained at 2, 6, 12, and 18 GHz, respectively. These low-noise characteristics of our HBT's show high potential for low-noise application     

Amino acids in maturation medium and presence of cumulus cells at fertilization promote male pronuclear formation in porcine oocytes matured and penetrated in vitro

The present study was conducted to examine the ability of porcine oocytes to achieve male pronuclear (MPN) formation when they are matured and penetrated in vitro under various culture conditions. When cumulus-enclosed oocytes were cultured for 24-48 h in modified Whitten's medium (pH 7.4) supplemented with 10% porcine follicular fluid, 10 IU eCG/ml, and 10 IU hCG/ml (designated mWM-FG), nuclear maturation of oocytes reaching metaphase II was completed by 36 h after the start of culture. However, there were no differences in the proportions (94-95%) of oocytes penetrated in vitro by cryopreserved ejaculated spermatozoa or in the rates (35-45%) of MPN formation between oocytes cultured for 36 and 48 h. When cumulus-enclosed oocytes were cultured for 36 h in mWM-FG supplemented with 2% (v:v) minimal essential medium (MEM) essential amino acids (EAA) with the addition of 0.1 mM glutamine and/or 1% (v:v) MEM nonessential amino acids (NEAA) and inseminated in vitro, 93-97% of oocytes were penetrated regardless of the presence of amino acids during maturation, but the rates of MPN formation were higher in the presence (79-84%) than in the absence (51%) of any amino acids. The addition of EAA+NEAA and/or 0.57 mM cysteine to mWM-FG also did not affect sperm penetration in vitro, while it promoted MPN formation (76-83%) in penetrated oocytes as compared with those matured in the absence of amino acids and cysteine (53%). When oocytes were freed from cumulus cells after culture in mWM-FG, sperm penetration rates were not different between cumulus-enclosed (100%) and cumulus-free (92%) oocytes, but the rate of MPN formation was higher in cumulus-enclosed (53%) than in cumulus-free (28%) oocytes. When EAA+NEAA+cysteine was added to mWM-FG, MPN formation was not improved in cumulus-free oocytes but was much improved (78%) in cumulus-enclosed oocytes. These results indicate that MPN formation in porcine oocytes is promoted by the addition of amino acids and/or cysteine in simple maturation medium and by the presence of cumulus cells at fertilization in vitro.     

Effect of training program based on anaerobic threshold in the early phase after acute myocardial infarction

We devised a new physical training program on the basis of anaerobic threshold for rehabilitation in the early phase of acute myocardial infarction. Forty-four patients were divided into two groups, control and training. We measured the left ventricular ejection fraction using nuclear stethoscopy during the treadmill test and calculating radioactive cardiac output. In the training group, anaerobic threshold and exercise time to the anaerobic threshold point were significantly increased, and stroke volume at rest measured by the dye dilution method increased significantly. Radioactive cardiac output during exercise also increased after the exercise therapy. These results indicate that the rehabilitation program consisting of physical training based on the anaerobic threshold is effective.     

Immunohistochemical detection of estrogen and progesterone receptors in spermatozoa of infertile men

OBJECTIVE: To evaluate the clinical implication of sex steroidal actions on human spermatozoa. PATIENTS AND METHODS: Human spermatozoa were obtained from 20 males. Immunohistochemical staining for estrogen receptors (ER) and progesterone receptors (PR) was conducted by the avidin-biotin-peroxidase complex method. RESULTS: Positive immunohistochemical staining of ER and PR was observed in all 8 cases of fertile couples. From infertile couples, ER were detected in 8/12 cases, including 3 with normozoospermia, 2 with oligozoospermia, 1 with asthenozoospermia, and 2 with teratozoospermia, but not in 4/12 cases, 1 with normozoospermia, 1 with asthenozoospermia, and 2 with oligoasthenozoospermia. PR were undetectable in all cases of negative ER and in 1 case (normozoospermial) of positive ER. CONCLUSION: Negative ER and/or PR in spermatozoa from infertile couples might be involved in cases of male infertility.     

α-sulfonated fatty acid esters: II. Solution behavior of α-sulfonated fatty acid polyethylene glycol esters

Sodium α-sulfonated, fatty acid polyethylene glycol monoesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n H] and diesters [C _m H_2m+1CH(SO₃Na)COO(C₂H₄O) _n COCH(SO₃Na)C _m H_2m+1], wherem=10–16 andn=1–35, were prepared by esterification of α-sulfonated, fatty acids with polyethylene glycols, followed by neutralization with NaOH. Crude products were purified by reversed-phase column chromatography on an octadecyl-modified silica gel. Characteristic solution behavior of these α-sulfonated fatty acid esters was, examined, and the following features were observed. All monoesters prepared in this work had Krafft points below 0°C and also possessed good calcium stabilities. Critical micelle concentrations of the monoesters increased monotonously, as a rule, with an increase in the number of oxyethylene units. These results suggest that the polyethylene glycol residue of the monoester behaves as a hydrophile. On the other hand, diesters possessed high water solubility, low foamability, and critical micelle concentrations that were lower by a factor of ten compared to those of the monoesters.     

Preliminary results of fine needle aspiration biopsy histology in upper gastrointestinal submucosal tumors

To elucidate the characteristics of lung cancer complicated by pneumoconiosis, we compared the clinical features of complicated and uncomplicated lung cancer cases. The average age at onset was higher for patients with pneumoconiosis than for those without. Because pneumoconiosis presents various respiratory symptoms, subjective symptoms were less important than objective symptoms in detecting lung cancer complicated by pneumoconiosis. Although fiberoptic bronchoscopy was the predominant diagnostic method, it could not be used with the pneumoconiosis patients. Diagnoses of lung cancer complicated by pneumoconiosis were made more after by percutaneous needle aspiration cytology. Squamous cell carcinoma is the most frequent form of cancer in patients with pneumoconiosis, which suggests that the inhalation of carcinogens may play a role in the pathogenesis of lung cancer. With respect to the smoking index (SI), histological specimens indicated that the incidence of squamous cell carcinoma in patients with pneumoconiosis was significantly higher in heavy smokers (SI > or = 600) than in light smokers (SI < 600) or nonsmokers. It is suspected that smoking affects carcinogenesis of pneumoconiosis. No differences in the distribution of lung cancer (right-left, hilar-peripheral) distinguished the 2 groups. Many of the patients with peripheral-type lung cancer and pneumoconiosis had tumors in the lower lung lobes. These findings underline the importance of encouraging pneumoconiosis patients to avoid lung cancer by not smoking, and to have lung cancer detected in its early stages by undergoing regular medical exams.     

Comparison of susceptibility to apoptosis induced by rhTNF-alpha and cycloheximide between human circulating and exudated neutrophils

OBJECTIVE: Peroxynitrite and hydroxyl radical, reactive oxidants produced during reperfusion, are potent triggers of DNA single strand breakage. DNA injury triggers the activation of the nuclear enzyme poly (ADP-ribose) synthetase (PARS), which contributes to cellular energetic depletion. Using 3-aminobenzamide, an inhibitor of PARS, we investigated the role of PARS in the pathogenesis of myocardial reperfusion injury in a rat model. METHODS AND RESULTS: Occlusion of the left main coronary artery (one hour) followed by reperfusion (one hour) in the anesthetized rat caused severe cardiac necrosis, neutrophil infiltration, and increased plasma creatine phosphokinase activity. There was significant peroxynitrite production during reperfusion, as indicated by a massive increase in nitrotyrosine in the necrotic myocardium. Reperfusion was also associated with a significant loss of myocardial ATP. In vivo administration of the PARS inhibitor 3-aminobenzamide (10 mg/kg i.v.) to rats subjected to myocardial ischemia and reperfusion, reduced myocardial infarct size and blunted the increase in plasma creatine phosphokinase activity and myeloperoxidase activity in infarcted hearts. In addition, 3-aminobenzamide partially preserved the myocardial ATP levels. In vitro, pharmacological inhibition of PARS also ameliorated peroxynitrite-induced cytotoxicity in rat cardiac myocytes and human endothelial cells. CONCLUSION: 3-aminobenzamide has significant protective effects in myocardial reperfusion injury. We hypothesize that activation of PARS activation plays a role in the pathophysiology of acute myocardial infarction.     

High-sensitivity Hi-Lo germanium avalanche photodiode for 1.5 ?m-wavelength optical communication

A high-sensitivity small-detectable-area Hi-Lo germanium avalanche photodiode (Ge APD) was developed for use in 1.55 ?m wavelength optical communication systems. This device has Hi-Lo (p+nn?) impurity profile. Its detectable area is 30 ?m in diameter for single-mode optical-fibre use. The minimum average received signal level obtained was ?40.5 dBm (at 450 Mbit/s, ? = 1.55 ?m, BER = 10?9, return-to-zero). This is 0.7 dB better than the value for the 80?m diameter similar structure Ge APD.     

Inflammatory cytokine production in whole blood modified by liposome-encapsulated hemoglobin

The effect of Neo Red Cells (NRC), liposome-encapsulated hemoglobin, on production of tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) were studied in whole blood preparations ex vivo. Venous blood was collected with heparin and incubated in a CO2 incubator. Treatment of blood samples with NRC reduced the constitutive levels of TNF-alpha and IL-6. Lipopolysaccharide (LPS) treatment for 24 h increased production of TNF-alpha and IL-6 in a dose-dependent manner. Pretreatment with NRC (5%) for 24 h markedly potentiated the LPS-induced TNF-alpha production and, that of IL-6 to a lesser extent. Northern blotting analysis of total RNA in whole blood showed that pretreatment with NRC caused a marked increase in TNF-alpha mRNA expression in response to LPS. It is concluded that NRC potentiates LPS-induced TNF-alpha and IL-6 production in whole blood ex vivo, and that the potentiating effect of NRC on LPS-induced TNF-alpha production can be attributed, at least in part, to an increase in its mRNA expression.