Physical Mechanism of the Transverse Instability in Radiation Pressure Ion Acceleration.

The transverse stability of the target is crucial for obtaining high quality ion beams using the laser radiation pressure acceleration (RPA) mechanism. In this Letter, a theoretical model and supporting two-dimensional (2D) particle-in-cell (PIC) simulations are presented to clarify the physical mechanism of the transverse instability observed in the RPA process. It is shown that the density ripples of the target foil are mainly induced by the coupling between the transverse oscillating electrons and the quasistatic ions, a mechanism similar to the oscillating two stream instability in the inertial confinement fusion research. The predictions of the mode structure and the growth rates from the theory agree well with the results obtained from the PIC simulations in various regimes, indicating the model contains the essence of the underlying physics of the transverse breakup of the target.

Serum levels of interleukin-8 in alcoholic liver disease: relationship with disease stage, biochemical parameters and survival.

BACKGROUND/AIMS: Interleukin-8 (IL-8), a cytokine produced by a host of cells, including monocytes, macrophages, Kupffer cells and hepatocytes, can activate neutrophils. Peripheral neutrophilia and liver neutrophil infiltration are frequently noted in patients with alcoholic liver disease. However, the relationship between IL-8 and different stages of alcoholic liver disease is uncertain. The aim of this study is to determine if a correlation exists between circulating IL-8 levels and biochemical and histological parameters and survival in alcoholic liver disease. METHODS: Serum levels of IL-8 were determined with an enzyme-linked immunosorbent assay in 166 subjects, consisting of 30 healthy controls, 26 patients with non-alcoholic fatty liver, 15 with alcoholic fatty liver, 32 with alcoholic hepatitis, 30 with alcoholic cirrhosis, 28 with chronic hepatitis B and 5 with chronic hepatitis C. RESULTS: Serum IL-8 levels were markedly elevated in patients with alcoholic hepatitis (437 +/- 51 pg/ml) when compared with all other groups (p < 0.05). Levels of IL-8 in patients with alcoholic fatty liver, alcoholic cirrhosis and viral hepatitis were higher than those in controls and in patients with non-alcoholic fatty liver. In addition, IL-8 levels were higher in patients who died (p = 0.007), and correlated with biochemical and histological parameters, and severity of liver injury: serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, prothrombin time, indocyanine green retention ratio, tumor necrosis factor-alpha and peripheral neutrophil count in patients with alcoholic hepatitis. After a 2-year follow up, patients with IL-8 above 479 pg/ml had a higher mortality rate in the alcoholic hepatitis group (p = 0.033). CONCLUSIONS: These findings suggest that IL-8 is activated in alcoholic liver disease, especially in alcoholic hepatitis, and is closely correlated with liver injury. IL-8 levels can reflect the stage and severity of alcoholic liver disease, and may serve as a predictor of survival in patients with alcoholic hepatitis.

Traumatic dislocations of the distal carpal row.

13 patients who sustained high-energy crush or blast injury of the carpal bones were reviewed after a mean follow-up period of 30 months. These complex injuries resulted in unusual disruptions of the distal carpal row and adjacent metacarpals. Frequent involvement of the carpometacarpal (CM) joints and violation of the proximal carpal row were also demonstrated. Nine were open injuries, with the majority accompanied by significant soft tissue damage. Treatment included either closed reduction or open reduction and Kirschner wire fixation, and soft tissue procedures as indicated. In this series, the majority of the open injuries gave unfavourable functional results despite adequate carpal alignment. Several cases had disastrous outcomes related to associated vascular injuries. Closed injuries, on the contrary, followed a relatively benign course. Nevertheless, decreased grip strength persisted in both groups for a long time. Patients with such a complex carpal injury should expect a less favourable prognosis due to the severe nature of the trauma.

Dupuytren's contracture: report of a Taiwanese case.

This case of Dupuytren's contracture was seen in a 65-year-old Taiwanese male farmer patient. The patient complained of a progressive inability to fully extend the ring and middle fingers of his dominant hand over the last three years. Clinically, a longitudinal cord-like mass surrounded the distal palmar crease of the hand and digital flexion contraction of the ring finger was more affected than the middle finger. Histopathologically, the excised tissue was of a mixed, moderate and scantily cellular type. After surgical treatment by limited fasciectomy, the patient's hand recovered fully. No recurrent contracture was noted after three years of follow-up.

High-pressure injection injuries of the hand.

The majority of high-pressure injection injuries can produce serious damage to the hand. Nevertheless, the injury may follow a relatively benign course if the injected substance possesses a less harmful nature. Treatment for these injuries requires immediate and aggressive surgery in most circumstances, but conservative treatment may be justified in certain instances. During a 4-year period, eight cases of high-pressure injection injury were encountered. The types of injected material were: four from paint, and one each from grease, water, benzene, and hydraulic oil. Time is an important factor regarding the results, while the types of injected material modify the clinical courses. It is advisable that the etiology of high-pressure injection injury should be established initially, and this factor be taken into consideration in choosing treatment options.

In situ enzyme immunoassay for antiviral susceptibility testing of respiratory syncytial virus.

An enzyme immunoassay (EIA), performed directly on fixed infected monolayers of HEp-2 cells in microtiter plates, was compared with the conventional plaque reduction assay (PRA) method for the determination of antiviral activity of ribavirin against respiratory syncytial virus. A 50% reduction in virus replication was observed at 3.4 and 5.9 mg/L of the drug by EIA and PRA, respectively. EIA is simple to perform and reproducible and has objective end points. Moreover, EIA has advantages over PRA in that results are available sooner and a much wider range of inoculum size can be used without affecting susceptibility data. EIA is suitable for the rapid susceptibility and accurate testing of a large number of clinical isolates.

Selective and differential medium for recovery of Pseudomonas cepacia from the respiratory tracts of patients with cystic fibrosis.

A selective and differential medium, OFPBL (oxidation-fermentation base supplemented with agar, lactose, and two antimicrobial agents), for the isolation of Pseudomonas cepacia from respiratory specimens of patients with cystic fibrosis was developed and tested. Among 725 specimens submitted from seven centers over a 4- to 6-month period, 58 (8%) yielded P. cepacia on OFPBL; only 19 of these were recovered on MacConkey or sheep blood agar (P less than 0.001). No isolate was recovered on MacConkey or sheep blood agar alone. Ranges of recovery rates among centers were 0 to 15% on OFPBL and 0 to 10% on MacConkey or sheep blood agar. Ninety percent of P. cepacia isolates were detected on OFPBL in less than or equal to 3 days. Other nonfermenters and yeasts isolated on OFPBL were distinguished from P. cepacia by failure to acidify the medium. The new medium was clearly superior to MacConkey and sheep blood agars for the isolation of P. cepacia from the respiratory secretions of patients with cystic fibrosis.

The histopathology of rectosigmoid biopsies from adults with bloody diarrhea due to verotoxin-producing Escherichia coli.

The histopathology of rectosigmoid biopsies from 20 patients with bloody diarrhea resulting from verotoxin-producing Escherichia coli infection is reported. The biopsies displayed a range of appearances, from normal to mild, nonspecific inflammation to acute infectious-type colitis. Surface-adherent or invasive bacteria were not identified. The morphologic features of infectious colitis and the absence of bacteria suggest that verotoxin may be responsible for the pathologic changes.

Partial purification and properties of D-desthiobiotin synthetase from Escherichia coli.

d-Desthiobiotin synthetase, an enzyme that catalyzes the synthesis of d-desthiobiotin from dl-7,8-diaminopelargonic acid and HCO(3) (-), was purified 100-fold from cells of a biotin mutant strain of Escherichia coli. Adenosine triphosphate and Mg(2+) were shown, especially in purified extracts, to be obligatory for enzyme activity, although concentrations higher than 5 mm caused severe inhibition of the reaction with unpurified cell-free extracts. Adenosine diphosphate and adenosine monophosphate were shown to inhibit the reaction, but fluoride (up to 50 mm) had no detectable effect. The product of the enzyme reaction was identical to d-desthiobiotin on the basis of biological activity and chromatography. Furthermore, when H(14)CO(3) (-) was used as a substrate, the radioactive product was shown to be (14)C-desthiobiotin labeled exclusively in the ureido carbon.