Enhanced 400-600 nm photoresponsivity of metal-oxide-semiconductor diodes with multi-stack germanium quantum dots

Metal-oxide-semiconductor (MOS) diodes with zero-, one- or three-layer Ge quantum dots (QDs) embedded in the gate oxide are fabricated for visible to near-ultraviolet photodetection. Ge dots are formed by thermally oxidizing one or three stacks of amorphous Si (a-Si)/polycrystalline-Si(0.87)Ge(0.13)/a-Si multi-layers that are sandwiched by SiO(2) barriers. The current-voltage characteristics of Ge QD MOS diodes exhibit strong rectification in darkness and feature significant current enhancement in the inversion mode when illuminated. Increasing the number of Ge QD layers from zero through one to three in the gate oxide improves the responsivity from 4.64 through 482 to 812 mA W(-1) and enhances the corresponding quantum efficiency from 1.42 through 148 to 245%, respectively. The spectral response reveals a considerable blueshift in peak energies as the Ge dot size decreases from 9.1 to 5.1 nm, suggesting that the light absorption originates from the quantum confinement effect of Ge QDs. The temperature and bias dependences of the dark current indicate that the carrier transport mechanism involves percolation hopping.

Expression of soluble form carp (Cyprinus carpio) ovarian cystatin in Escherichia coli and its purification

A DNA encoding thioredoxin-mature carp ovarian cystatin (trx-cystatin) fusion protein was ligated into a pET-23a(+) expression vector and then transformed into Escherichia coli AD494(DE3) expression host. After induction by isopropyl beta-D-thiogalactopyranoside, a high level of the soluble form of recombinant trx-cystatin was expressed in the cytoplasm of E. coli. The recombinant trx-cystatin could be purified by Ni(2+)-NTA agarose affinity chromatography. The molecular mass (M) of the recombinant trx-cystatin was approximately 28 kDa composed of recombinant thioredoxin (16 kDa) and recombinant mature carp ovarian cystatin (12 kDa). Both recombinant trx-fused and mature carp ovarian cystatins were stable at pH 6-11. No obvious decrease in activity was observed even after 5 min of incubation at 60 degrees C. They exhibited papain-like protease inhibition activity comparable to that of the mature carp ovarian cystatin, which could inhibit papain and mackerel cathepsins L and L-like, but not cathepsin B.

Purification and characterization of calpastatin from grass prawn muscle (Penaeus monodon)

Calpastatin, a specific calpain inhibitor was purified to electrophoretical homogeneity from grass prawn (Penaeus monodon) muscle by 100 degrees C heat-treatment, DEAE-Sephacel, and Q-Sepharose chromatographs. No significant change in the inhibitory activity of crude calpastatin was observed even after 20 min incubation at 100 degrees C, pH 7.0. The purified prawn calpastatin had a molecular weight (M(r)) of 80 and 88.7 kDa determined by SDS-PAGE and Sephacryl S-200 HR gel filtration, respectively. According to the active site titration, the purified calpastatin revealed four beef mu-calpain and two beef m-calpain binding domains, respectively. It was stable during 1 h of incubation at 30 degrees C under pH 4.5-10.0 and shown to be a highly specific inhibitor for calpain.

Relationships of orbital computed tomographic findings and activity scores to the prognosis of corticosteroid therapy in patients with Graves' ophthalmopathy

To elucidate the relationships of orbital computed tomographic findings and activity scores to the prognosis of corticosteroid therapy in patients with Graves' ophthalmopathy, 22 cases were treated with corticosteroid. Orbital computed tomographic was performed before treatment and the maximal muscle areas of rectus muscle bellies were calculated from the coronal images. Activity scores were calculated according to the recommendations of an international ad hoc committee. The clinical severity of the eye disease was based on the NOSPECS classification. Observation of the effectiveness of treatment at 6 months allowed patients to be classified into good responders or poor responders. Twelve of 22 patients (54.5%) belonged to the good responders. The total muscle areas were less in good responders. Although the total muscle areas were significantly correlated with the activity scores, no difference in the activity scores was noted between these two groups. We concluded that although activity score seems to be a predictor of initial responsiveness to anti-inflammatory drugs, the maximal muscle area is a prognostic factor of corticosteroid therapy in patients with Graves' ophthalmopathy.

Therapeutic responses to corticosteroids in Graves' ophthalmopathy

To elucidate the therapeutic responses to corticosteroids and prognostic factors in the treatment of Graves' ophthalmopathy, 23 patients with Graves' ophthalmopathy were treated with intravenous methylprednisolone 0.5 g daily for 3 days, followed by prednisolone 40 mg daily. Dosage was reduced gradually to 10 mg daily over 4 weeks. The symptoms and signs of the eyes were recorded. Orbital computed tomography and urinary glycosaminoglycan excretion testing were performed before treatment. We observed the effectiveness of treatment at 6 months as the endpoint of this study and classified the response as good or poor. We compared the differences in parameters between these two groups. The results showed that 12 (52%) out of 23 patients had a good response, and three (25%) of those with a good response recovered completely. Corticosteroid therapy dramatically improved lacrimation, reduced soreness and congestion of the eyes and ameliorated exophthalmos, lagophthalmos and extraocular muscle movement. Four (36%) of the 11 patients with a poor response had rebound of symptoms and/or signs after the dosage of prednisolone was decreased. Those with a good response were usually younger, and enlargement of the extraocular muscle was also milder than in those with a poor response. This study demonstrated that corticosteroid therapy is effective in Graves' ophthalmopathy and that extraocular muscle size demonstrated by orbital computed tomography is a prognostic factor of therapy.

Relationship of eye movement to computed tomographic findings in patients with Graves' ophthalmopathy

To elucidate the relationship between eye movement and computed tomographic findings, 101 patients with Graves' ophthalmology were studied. Eye movements were scaled 0 to 3 according to movability. Extraocular muscle width and area were calculated from the largest portion of each muscle from the orbital coronal CT sections. Muscle widths were measured manually and muscle areas were calculated by a digitizer. The width and area of each rectus muscle were significantly correlated with limitation of eye movement. The muscle widths and areas were also significantly correlated to each other (r = 0.91 to 0.77, p < 0.001). Limitations of supraduction and abduction from enlargement of the inferior and medial rectus muscles were the most common clinical findings (46.5% and 39.6%, respectively). In conclusion, this study establishes a relationship between limitation of eye movement and extraocular muscle enlargement. Calculation of the width from the largest portion of the muscle manually from orbital coronal section is a simple method for clinical assessment of the severity of extraocular muscle involvement.

[Ischemic stroke in Taiwan]

An extensive survey of stroke in Taiwan was carried out by members of the Neurological Society, R.O.C. (Taiwan). Of a total 7,355 acute stroke patients who were admitted to 26 teaching hospitals in Taiwan (January 1 through December 31, 1985), there were 3,949 (53.7%) patients of cerebral infarction (CI). There was little seasonal variation in CI occurrence. In 90.5% of CI patients, the age of onset was above 50 years. The male to female ratio was 1.51:1. Hypertension was noted in 2,648 patients (67.1%), diabetes in 1,030 (22.9%), and heart disease in 953 (17.4%). A previous history of one or more strokes was obtained in 24.6% of the CI patients, and transient ischemic attacks (TIAs) in 6.4%. The stroke onset during the ordinary activities was noted in 41.1% of the CI patients, during sleep in 12.8% and at rest in 9.9%. CI occurred most frequently in the morning hours (24.0%). The majority of patients (85.9%) underwent computed tomography which provided valuable information in making distinction between cerebral infarction and cerebral hemorrhage. Angiography was performed in 3.3% of the patients for visualizing the stenosis and/or occlusion of the intracranial and the extracranial vessels. The mortality rate for CI was 8.4%, and 49.4% of fatal cases died within the first week after onset. At the time of discharge, the stroke survivors were rated "recovered" in 10.8% of CI patients, "minimally disabled" in 26.3%, "moderately disabled" in 38.0% and "severely disabled" in 16.9%.

The latencies of sympathetic skin responses

The sympathetic skin response (SSR) was measured in 35 normal healthy adults and in 40 patients with diabetic polyneuropathy. When recording from the hand or the foot, the SSR latency was the same whether stimulating at the hand or the foot. This may suggest that the conduction velocity of afferent fibers is much faster than that of efferent fibers, so that the former do not contribute to the SSR latency. The SSR amplitudes were significantly reduced in diabetic patients (p < 0.001), but their latencies were normal as long as responses could be detected. It is possible that some surviving unmyelinated fibers and/or regenerated fibers take the responsibility for normal conduction. Another possible explanation is that the postganglionic unmyelinated fibers in polyneuropathy may represent themselves as 'all or none', i.e., either the fibers conduct with normal velocity or they do not conduct at all.

Monitoring of serum neopterin in renal transplant recipients

Postoperative management of kidney allograft recipients requires a reliable and rapid diagnostic method so that proper therapy can be initiated. In this study, we tried to correlate serum neopterin levels with different conditions after transplantation. Serial serum neopterin levels were assessed after operation. Serum neopterin levels of uremic patients were significantly higher than those of healthy persons (239.9 +/- 177.7 nmole/L, n = 33 vs 6.14 +/- 2.78 nmole/L, n = 10, p < 0.001). In recipients with a stable post-transplant course, the serum neopterin level was low. On the contrary, acute rejection episodes were associated with a high level of serum neopterin which declined after successful treatment, although the difference was not significant (96.2 +/- 57.7 nmole/L vs 56 +/- 38.1 nmole/L, p > 0.05). The serum neopterin level was also high in post-transplant acute tubular necrosis (ATN, 256.6 nmole/L), which gradually declined parallel to the resolution of ATN. The neopterin level was low in patients with cyclosporine nephrotoxicity (17.8 +/- 7.6 nmole/L). In summary, the serum neopterin levels were persistently high in uremic and post-transplant ATN patients. Acute rejection episodes were correlated with an increased level of neopterin. It appears that daily measurement of the serum neopterin level may be useful for biochemical detection of immunologic complications in allograft recipients.

Lymphokinetic monitoring of a liver transplant recipient treated with OKT3

Orthotopic liver transplantation was performed on a 48-year-old female patient with end-stage liver disease due to primary biliary cirrhosis. A course of OKT3 (5 mg/kg intravenously for 14 days) was given as immunosuppressive therapy. Lymphocyte population, T lymphocyte subsets and the lymphokine level in the peripheral blood were serially measured. Total T cells disappeared in the peripheral circulation within 10 minutes after an injection of OKT3. Helper T cells and suppressor T cells were also suppressed during the course of treatment. The ratio of T4/T8 declined from 2.5 to around 1.3. The serum interleukin-2 and the interleukin-2 receptor did not change markedly during treatment. The serum neopterin level increased after discontinuation of OKT3. The anti-mouse OKT3 antibody increased after the ninth day of OKT3 treatment. OKT3 showed potent T cell suppressive activity.

Common carotid artery dissection diagnosed by ultrasonic image: report of a case

Carotid artery dissection is not uncommon and usually starts at the internal carotid artery. It rarely begins in the common carotid artery. It may cause symptoms of cerebral vascular insufficiency such as stroke and transient ischemic attacks. The case reported here is a 38-year-old man with an acute onset of left hemiparesis 2 hours after drinking three bottles of beer. Computed tomographic scan showed cerebral infarction in the territory of the right middle and anterior cerebral arteries. Ultrasonic imagings showed an intimal flap, starting at the bifurcation of the right common carotid artery, indicative of arterial dissection. Angiography confirmed the diagnosis and the arterial dissection appeared to extend into and terminate at the internal carotid artery.

Proximal slowing of nerve conduction velocity in carpal tunnel syndrome

Slowing of median nerve conduction velocity (NCV) over the forearm segment is often seen in patients with carpal tunnel syndrome (CTS). In order to evaluate the extent and significance of this retrograde slowing of NCV, we examined 132 CTS hands from 84 patients diagnosed by both clinical and electrophysiological findings and both hands of 50 normal subjects. The mean median motor NCV was relatively slow in the CTS group (55.8 +/- 4.4 m/s) as compared with normal subjects (60.0 +/- 3.4 m/s, p less than 0.001). Mean median motor NCV was slower in CTS with low median motor amplitudes (less than 6.0 mV), 50.9 +/- 5.7 vs 56.1 +/- 4.1 m/s, p less than 0.001; and absent median sensory responses, 51.8 +/- 5.3 vs 56.0 +/- 4.3 m/s, p less than 0.001. There were 14 CTS hands with abnormally slowed median motor NCV (less than 50 m/s). This group had significantly lower median sensory and motor amplitudes, and longer motor distal latencies and sensory wrist-palm conduction time as compared with CTS hands with normal median motor NCV (greater than 50 m/s), p less than 0.001 for each parameter. These findings indicate that the proximal median motor NCV is usually affected by the distal lesion of CTS. Furthermore, the motor nerve conduction velocity proximal to the wrist is reduced in proportion to the severity of the nerve lesion. Electromyographers should be aware of this phenomenon and avoid the error of lesion localization.

Respiratory paralysis as a presenting symptom in Japanese encephalitis--a case report

In the literature there are rare reports on Japanese encephalitis (JE) mimicking poliomyelitis or presenting as respiratory paralysis. A case of JE presenting as respiratory paralysis is described. The 22-year-old male was well until five days earlier, when he experienced the acute onset of headache and fever. Four days after onset he developed dysphagia and respiratory difficulty, and a tracheotomy was performed. The following day he lapsed into semicoma and the respiration had to be maintained by an artificial ventilator. He regained consciousness by the 10th day after onset. He became able to comprehend questions and express himself by gestures. But the respiration was still paralytic, and assisted ventilation via a tracheotomy had to be continued. The case was clinically diagnosed as encephalitis. Bulbar poliomyelitis was initially considered due to the clinical features of aseptic meningitis, respiratory paralysis, pharyngeal paralysis with pooling secretions in the pharynx, tachycardia and elevated blood pressure. But poliovirus culture obtained from stool and appropriate serological studies were negative. The diagnosis of encephalitis due to JE virus was confirmed by hemagglutination inhibition test (acute phase HI titer 1:320; convalescent phase HI titer 1.1280).