Vertical-cavity and randomly scattered lasing from different thicknesses of epitaxial ZnO films grown on Y₂O₃-buffered Si (111)

Two different types of lasing modes, vertical Fabry-Perot cavity and random lasing, were observed in ZnO epi-films of different thicknesses grown on Si (111) substrates. Under optical excitation at room temperature by a frequency tripled Nd:YVO₄ laser with wavelength of 355 nm, the lasing thresholds are low due to high crystalline quality of the ZnO epitaxial films, which act as microresonators. For the thick ZnO layer (1,200 nm), its lasing action is originated from the random scattering due to the high density of crack networks developed in the thick ZnO film. However, the low crack density of the thin film (555 nm) fails to provide feedback loops essential for random scattering. Nevertheless, even the lower threshold lasing is achieved by the Fabry-Perot cavity formed by two interfaces of the thin ZnO film. The associated lasing modes of the thin ZnO film can be characterized as the transverse Gaussian modes attributed to the smooth curved surfaces.

Single domain m-plane ZnO grown on m-plane sapphire by radio frequency magnetron sputtering

High-quality m-plane orientated ZnO films have been successfully grown on m-plane sapphire by using radio frequency magnetron sputtering deposition. The introduction of a nanometer-thick, low-temperature-grown ZnO buffer layer effectively eliminates inclusions of other undesirable orientations. The structure characteristics of the ZnO epi-layers were thoroughly studied by synchrotron X-ray scattering and transmission electron microscopy (TEM). The in-plane epitaxial relationship between ZnO and sapphire follows (0002)(ZnO) [parallel] (112[overline]0)(sapphire) and (112[overline]0)(ZnO) [parallel] (0006)(sapphire) and the ZnO/sapphire interface structure can be described by the domain matching epitaxy along the [112[overline]0](ZnO) direction. The vibrational properties of the films were investigated by polarization dependent micro-Raman spectroscopy. Both XRD and micro-Raman results reveal that the obtained m-ZnO layers are under an anisotropic biaxial strain but still retains a hexagonal lattice.

Factors associated with women's and children's body mass indices by income status

OBJECTIVE

To describe associations between eating behaviors, dietary intake, physical activity, attitudes toward diet and health, sociodemographic variables and body mass index (BMI) among women and children, and differences by household income.

DESIGN

Data from the 1994-1996 Continuing Survey of Food Intakes by Individuals (CSFII) and the Diet and Health Knowledge Survey (DHKS) were examined using multivariate regression to estimate the associations between BMI and behavioral and environmental variables among women and children.

SUBJECTS

CSFII 1994-1996 is representative of the US population. DHKS surveyed CSFII respondents 20 y of age and over. Our samples consisted of 2419 adult women and 1651 school-age children.

MEASUREMENTS

CSFII respondents reported 24 h recalls of all food intakes on 2 nonconsecutive days and their personal and household characteristics, including self-reported height and weight. DHKS collected data on knowledge and attitudes toward dietary guidance and health from CSFII adult respondents.

RESULTS

Significant correlations between women's BMI and age, race, dietary patterns, TV watching, and smoking was observed among women from both low- and high-income households. Beverage consumption, eating out, the importance of maintaining healthy weight, and exercise were correlated with BMI only among women from high-income households. Among children, age, race, income, and mother's BMI were significantly correlated with child BMI.

CONCLUSIONS

Among women, the associations between some behavioral and environmental factors and BMI differ by household income. Intervention programs need to target specific eating and physical activity behaviors to promote a healthy body weight.

Choose a variety of grains daily, especially whole grains: a challenge for consumers

The 2000 edition of Nutrition and Your Health: Dietary Guidelines for Americans is the first to include a specific guideline for grain foods, separate from fruits and vegetables, and recognize the unique health benefits of whole grains. This paper describes and evaluates major tools for assessing intakes of total grains and whole grains, reviews current data on who consumes grain foods and where, and describes individual- and market-level factors that may influence grain consumption. Aggregate food supply data show that U.S. consumers have increased their intake of grain foods from record low levels in the 1970s, but consumption of whole-grain foods remains low. Data on individual intakes show that consumption of total grains was above the recommended 6 serving minimum in 1994-1996, but consumption of whole grains was only one third of the 3 daily servings many nutritionists recommend. Increased intake of whole-grain foods may be limited by a lack of consumer awareness of the health benefits of whole grains, difficulty in identifying whole-grain foods in the marketplace, higher prices for some whole-grain foods, consumer perceptions of inferior taste and palatability, and lack of familiarity with preparation methods. In July 1999, the U.S. Food and Drug Administration authorized a health claim that should both make it easier for consumers to identify and select whole-grain foods and have a positive effect on the availability of these foods in the marketplace.

Collateral pathways in superior vena caval obstruction as seen on CT

PURPOSE

Collateral venous pathways occurring with superior vena cava (SVC) obstruction were examined based on CT scans obtained from the thoracic inlet to the pubic symphysis. Similarities and variations from the prior classification scheme were analyzed.

METHOD

A retrospective review of our database resulted in a cohort comprising 21 CT scans from 19 patients. The location and frequency of each collateral pathway and the level of the SVC obstruction were tabulated. An accepted classification scheme was applied to the collateral patterns in each case. Additional and atypical features were noted.

RESULTS

Fifteen common collateral veins were found that could be grouped into one to four collateral pathways. Unusual shunts, including hepatic parenchymal and pulmonary pathways, were found. Thirteen cases (62%) varied from the standard classification owing to different occlusion levels or presence of other collaterals. No statistically significant relationship between the level of occlusion and the number of collateral pathway groups was found. The most common abdominal collateral veins were those along the liver surface (52.3% of cases), although 18 patients (94.7%) had at least one collateral vein visible in the abdomen.

CONCLUSION

The spectrum of venous collateral formations as seen on thoracoabdominal CT scans often includes collaterals at or below the level of the diaphragm, including intrahepatic shunts. Many collateral patterns found in this series could not be classified with the existent classification scheme.

What is the significance of nasal involvement in nasopharyngeal carcinoma?

PURPOSE

The purpose of this study was to differentiate the patterns of nasal fossa involvement in nasopharyngeal carcinoma (NPC) and to clarify its prognostic influence on local control and survival after radiation therapy.

METHODS AND MATERIALS

Between November 1989 and July 1991, 218 patients with histologically proven local-regional NPC were treated with radiotherapy following the protocol at the Department of Radiation Oncology, Cancer Hospital, Shantou University School of Medicine. All patients had pretreatment CT scans. Fiberoptic endoscopic examination was performed every week during treatment and at the time of every follow-up visit to define the initial extent of disease and to evaluate treatment response. No chemotherapy or brachytherapy was given.

RESULTS

Of the 218 patients, 87 had nasal involvement. Sixty of them had a pattern of mucosal infiltration (MI), another 27 had an exophytic protruding (EP) component. The likelihood of residual disease after irradiation, the local relapse rate, 5-year freedom from progression rate (FFP), and death rate associated with local relapse (DRALR) of MI and EP were 36.7% vs. 3.7%, 30.0% vs. 7.4%, 26.7% vs. 51.8%, and 25.0% vs. 3.7% with p<0.004, p<0.005, p<0.02, and p<0.03, respectively. Multivariate analysis in this selected group demonstrated that infiltration of nasal fossa mucosa was an independent prognostic factor on primary control and freedom from progression.

CONCLUSION

Differentiation of nasal fossa involvement according to MI or EP is of value in predicting the outcome of treatment. We suggest that only the MI group should be considered as nasal involvement in the staging of NPC.

CT findings after laparoscopic repair of ventral hernia

OBJECTIVE

We describe CT findings after laparoscopic repair of ventral hernia with emphasis on formation of postoperative fluid collections that can mimic recurrent bowel herniation or infected postoperative fluid collections.

CONCLUSION

The porous property of the mesh used in laparoscopic repair of ventral hernia allows reaccumulation of fluid in the existing hernia sac or spaces in the subcutaneous tissues that can be created by laparoscopic manipulation. These fluid collections should be expected and are differentiated from infected fluid collections or hernia recurrence by clinical presentation, laboratory data, and lack of ancillary features associated with true hernia such as presence of hernia sac, herniated mesentery, or bowel obstruction.

Treatment of inferior vena cava obstruction in hemodialysis patients using Wallstents: early and intermediate results

OBJECTIVE

The purpose of this study was to evaluate the efficacy of Wallstents in treating inferior vena cava obstruction in hemodialysis patients.

CONCLUSION

For the short and intermediate term, percutaneous placement of inferior vena cava Wallstents, followed by balloon angioplasty, is a safe and valuable technique for preserving the often limited central venous access in hemodialysis patients. To maintain patency, recurrent stenosis within the Wallstent can be treated with additional angioplasty.

Intracranial mycotic aneurysm in a patient with endocarditis caused by Cardiobacterium hominis

An intracranial mycotic aneurysm developed in a 35-year-old woman with endocarditis, caused by Cardiobacterium hominis, around a prosthetic valve. This type of aneurysm is a rare, life-threatening entity, and C. hominis is extremely uncommon as the causative agent. The pathogenesis and monitoring of intracranial mycotic aneurysm are discussed.

Nosocomial outbreak of scabies

Scabies is a common infestation caused by the human itch mite Sarcoptes scabiei. Small outbreaks in communities or hospitals are not uncommon, but are rarely documented. In this paper, we report on a nosocomial outbreak of scabies originating from a patient with Norwegian scabies at the Intensive Care Unit in Taiwan Provincial Tainan Hospital. Twenty-nine individuals including four inpatients and 25 hospital personnel were involved. The diagnosis was based on history, clinical findings or a positive skin scraping. Unfamiliarity with the clinical manifestations delayed the diagnosis and the highly contagious nature of Norwegian scabies precipitated this outbreak. Early initiation of effective control measures with extensive therapeutic and prophylactic treatment of all contacts resulted in successful eradication of the outbreak.

Serologic survey of spotted fever group rickettsiosis on Hainan Island of China

A serosurvey for antibodies to Rickettsia japonica was conducted on Hainan Island of China. Serum specimens were collected from 1,030 outpatients at hospitals in different parts of the island regardless of their diagnosis. Only two among 538 serum specimens collected in Baoting and Tongshi counties, located in the southern part of the island, were demonstrated to contain antibodies reactive with R. japonica at a high dilution. The specimens also reacted with R. rickettsii at the same titer as with R. japonica. These two specimens reacted with other pathogenic spotted fever group (SFG) rickettsiae to a lesser extent. On the other hand, the specimens were shown to possess antibodies reactive with R. typhi at a significantly lower dilution or were not reactive at all. The findings suggested the occurrence of an SFG rickettsiosis on Hainan Island. More than half of the serum specimens collected from patients with suspected rickettsial infections in the southern area were found to contain IgM and IgG antibodies to R. typhi, indicating a high incidence of murine typhus.

[Pelvic lipomatosis associated with cystitis glandularis--case report]

Pelvic lipomatosis is a rare benign disease of unknown etiology characterized by the proliferation of infiltrating fatty tissue within the deep bony pelvis. These fatty tissue may enclose the pelvic and retroperitoneal organs and various degrees of luminal compression and obstruction may happen. There is no typical presenting symptoms of pelvic lipomatosis. The major diagnostic methods are radiological examinations. CT scan is the definitive test to confirm the diagnosis. Open biopsy may be necessary when the diagnosis is inconclusive. Various treatment modalities have been tried, but only the diet therapy and complete ablation of fatty tissue ever reported to be successful. Cystitis glandularis, a rare proliferative inflammatory disease of the bladder, is reported to occur concurrently with pelvic lipomatosis in a patient. Herein we report a similar case. A middle-aged male patient was admitted with the chief complaint of painless gross hematuria for two weeks. After admission a series of radiological examinations and endoscopic bladder biopsy were performed. He was proved to be a rare case of pelvic lipomatosis associated with cystitis glandularis.

[Efficiency of patient-controlled analgesia versus conventional analgesia in patients after thoracotomy]

The patients received thoracotomy usually suffered from significant severe pain postoperatively, which accompanied with impaired pulmonary function or increased incidences of atelectasis and pneumonia. So adequate analgesia for those patients is indicated. The purpose of this study is to investigate the efficiency of patient-controlled analgesia (PCA) and determine whether it is better than conventional analgesia or not. Twenty-six patients, ASA physical status class I and II, were randomized into two groups: PCA and intramuscular (IM). The effect on pain relief was assessed by a visual analogue pain scale (VAPS) q 4 h postoperatively for two days. Forced vital capacity (FVC) and the questionnaire of nocturnal sleep disturbance by pain were evaluated preoperatively, the first, second postoperative mornings. As result of this study, the patients of PCA group get less pain than IM group after the first and second days of surgery. VAPS values are 3.7 +/- 1.1, 2.8 +/- 0.8 and 6.1 +/- 0.9, 5.3 +/- 1.1 respectively pertaining to PCA and IM groups (p less than 0.05). The patients of IM group get more disturbance of nocturnal sleep than PCA group at initial two nights of postoperation as well (p less than 0.05). It is manifest to look out the significant difference between these two groups in accordance with FVC ratio records of post-surgery vs presurgery at initial two days after surgery on the subject of respiratory function recovery. PCA group are 46.46 +/- 7.29%, 52.25 +/- 8.32% in a condition of more progress on lung function recovery than IM group of 38.13 +/- 10.25%, 42.15 +/- 7.82% (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Conformation of one- and two-chain high molecular weight urokinase analyzed by small-angle neutron scattering and vacuum ultraviolet circular dichroism

The structures of one- and two-chain high molecular weight human urokinase were analyzed by small-angle neutron scattering and vacuum ultraviolet circular dichroism. Both one- and two-chain high molecular weight urokinases exhibited a radius of gyration of 31 A and a maximum dimension of 90 A. Neither parameter was affected by the presence of lysine sufficient to saturate all the lysine-binding sites in human plasminogen. These physical parameters are consistent with the sedimentation coefficient of high molecular weight urokinase and indicate that both proteins are highly asymmetric. Neither protein contained much alpha-helix or parallel beta-sheet. Most of the secondary structure was in the form of antiparallel beta-sheet and beta-turns, very similar to the secondary structure of plasminogen. The macroscopic kinetic constants, Km and kcat, for the hydrolysis of (pyroGlu-Gly-Arg-NH)2-rhodamine by two-chain high molecular weight urokinase and low molecular weight urokinase which lacks the epidermal growth factor and kringle domains were similar. These structural and kinetic data are consistent with the domains in both forms of urokinase being independent structural and functional units.

[Effect of succinylcholine on recovery of atracurium-induced neuromuscular blockade]

If muscle relaxation is inadequate at the end of surgery, a transient increase in neuromuscular (NM) blockade should be needed to facilitate closure. Succinylcholine is the only agent of short duration available currently and could be used in the just mentioned circumstance. Therefore, the study was designed to investigate the effects of succinylcholine on the recovery of atracurium-induced NM blockade. Sixty-four female patients who underwent elective surgery under general anesthesia were allocated into 6 groups. Before anesthesia, no patient had received drugs which affect NM transmission. In all patients anesthesia was induced with thiopental, diazepam and fentanyl and maintained with 50% nitrous oxide in oxygen and 0.5-1.5% isoflurane. During anesthesia, blood pressure and electrocardiogram were monitored and end-tidal CO2 was maintained at 30-40 mmHg. Control records of the integrated electromyography responded to train-of-four supramaximal stimulation using a Datex Relaxograph were obtained after induction of anesthesia before a block was produced with an initial dose of succinylcholine 1.0 mg in group I (n = 8) or atracurium 0.4 mg/kg in groups II-VI. On first twitch (T1) recovering to 50% of control, 0.4 mg/kg, 0.6 mg/kg, 0.8 mg/kg, 1.0 mg/kg and 1.2 mg/kg of succinylcholine were given in groups II (n = 11), III (n = 14), IV (n = 11), V (n = 10), VI (n = 10) respectively. It was seen that succinylcholine 0.4 mg/kg antagonized NM blockade by atracurium but at 0.6 mg/kg, 0.8 mg/kg, 1.0 mg/kg, 1.2 mg/kg it enhanced that.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transfusion-induced severe allergic reaction--report of one case]

Recently, improved cross-matching techniques have reduced the frequency of adverse reactions of blood transfusion less the 2%, but allergic reactions (non-hemolytic) occur in about 3% of patients receiving properly typed and crossmatched blood. Allergic reactions to blood or drugs administered during anesthesia represent an unpredictable and occasionally life-threatening event. When a severe allergic reaction develops, an aggressive and prompt treatment, including intravenous epinephrine, is necessary to minimize morbidity and mortality. We experienced a case of intraoperative shock due to blood transfusion. The case manifested with hypotension, tachycardia, cutaneous rash and bronchospasm during blood transfusion and then the aggressive treatment was given to resume normal vital signs. The rest of anesthesia and surgery as well as the recovery was uneventful and the patient was discharged on the 18th postoperative day.

Characterization of an extremely large, ligand-induced conformational change in plasminogen

Native human plasminogen has a radius of gyration of 39 angstroms. Upon occupation of a weak lysine binding site, the radius of gyration increases to 56 angstroms, an extremely large ligand-induced conformational change. There are no intermediate conformational states between the closed and open form. The conformational chang is not accompanied by a change in secondary structure, hence the closed conformation is formed by interaction between domains that is abolished upon conversion to the open form. This reversible change in conformation, in which the shape of the protein changes from that best described by a prolate ellipsoid to a flexible structure best described by a Debye random coil, is physiologically relevant because a weak lysine binding site regulates the activation of plasminogen.

The purification and biological activity of a macrophage-derived factor with interleukin 1-like activities from guinea pigs

A macrophage-derived factor with interleukin 1-like activity was purified from culture supernatant of muramyl dipeptide-stimulated peritoneal exudate macrophages of guinea pigs. Starting with serum-free culture supernatant, the purification was carried out by gel permeation chromatography, affinity chromatography on procion red agarose, removal of carry-over serum proteins by Sepharose-coupled antibodies against bovine serum proteins, anion exchange chromatography and hydrophobic chromatography. The purified sample potentiated the phytohemagglutinin-induced thymidine uptake of thymocytes with a 50% effective concentration of 9.6 X 10(-11) M. The sample showed a single band in polyacrylamide gel electrophoresis, and a 65 kDa band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis by silver staining. A single peak of activity was detected by thymocyte assay at the position corresponding to the stained band in both of the electrophoretic analyses. The purified factor had activities to potentiate the antigenic activation of sensitized T cells for the production of a lymphokine, macrophage migration inhibitory factor, and also the proliferative response of sensitized T cells to antigen. Thus, the 65 kDa factor has activities to modulate various T cell responses in guinea pigs such as interleukin 1 does in other species. The molecular relationship of the 65 kDa macrophage factor to interleukin 1 remains to be determined.

Demonstration of the involvement of interleukin 2 in the differentiation of Staphylococcus aureus Cowan I-stimulated B cells

The effect of IL 2 on Staphylococcus aureus Cowan I (SAC)-driven IgG production of human B cells was examined by utilizing chromatographically purified IL 2 (R-IL 2) and the transcription product of the cloned cDNA for human IL 2 purified from recombinant E. coli (G-IL 2). Both preparations of IL 2 by themselves were not enough to induce optimal IgG-production in the SAC-stimulated tonsillar B cell fraction, which was highly enriched for B cells, but effectively induced IgG production in the presence of a subeffective number of T cells or a late-acting B cell differentiation factor (BCDF). In addition, the activity that induced IgG production in the presence of a subeffective number of T cells was absorbed with an IL 2-dependent mouse T cell line. These results clearly indicate that IL 2 has a definite effect on B cell differentiation in this system. Although the mechanisms of this effect remain to be elucidated, a direct effect of IL 2 on B cells may be involved, because the addition of IL 2 along with SAC induced a limited but significant increase of 3H-TdR incorporation in the highly enriched B cell population, which showed very little response to PHA and Con A even in the presence of IL 2, and, as mentioned above, IL 2 induced IgG production in the B cell preparation without any supplement of T cells provided the late-acting BCDF fraction was present in the culture.

Demonstration of the involvement of interleukin 2 in the differentiation of Staphylococcus aureus Cowan I-stimulated B cells

The effect of IL 2 on Staphylococcus aureus Cowan I (SAC)-driven IgG production of human B cells was examined by utilizing chromatographically purified IL 2 (R-IL 2) and the transcription product of the cloned cDNA for human IL 2 purified from recombinant E. coli (G-IL 2). Both preparations of IL 2 by themselves were not enough to induce optimal IgG-production in the SAC-stimulated tonsillar B cell fraction, which was highly enriched for B cells, but effectively induced IgG production in the presence of a subeffective number of T cells or a late-acting B cell differentiation factor (BCDF). In addition, the activity that induced IgG production in the presence of a subeffective number of T cells was absorbed with an IL 2-dependent mouse T cell line. These results clearly indicate that IL 2 has a definite effect on B cell differentiation in this system. Although the mechanisms of this effect remain to be elucidated, a direct effect of IL 2 on B cells may be involved, because the addition of IL 2 along with SAC induced a limited but significant increase of 3H-TdR incorporation in the highly enriched B cell population, which showed very little response to PHA and Con A even in the presence of IL 2, and, as mentioned above, IL 2 induced IgG production in the B cell preparation without any supplement of T cells provided the late-acting BCDF fraction was present in the culture.