Hepatitis C: Part I. Routine serologic testing and diagnosis

Hepatitis C, which is caused by the hepatitis C virus (HCV), is a major public health problem in the United States. HCV is most efficiently transmitted through large or repeated percutaneous exposures to blood. Most patients with acute HCV infection develop persistent infection, and 70 percent of patients develop chronic hepatitis. HCV-associated chronic liver disease results in 8,000 to 10,000 deaths per year, and the annual costs of acute and chronic hepatitis C exceed $600 million. An estimated 3.9 million Americans are currently infected with HCV, but most of these persons are asymptomatic and do not know they are infected. To identify them, primary health care professionals should obtain a history of high-risk practices associated with the transmission of HCV and other bloodborne pathogens from all patients. Routine testing is currently recommended only in patients who are most likely to be infected with HCV.     

Multilayer film preparation of poly(4-vinylphenol) from aqueous media

The use of weak polyelectrolytes in multilayer polymer systems provides a means of altering the physico-chemical properties of these thin films. This paper examines the limits of the polyanions by incorporating the extremely weak polyelectrolyte, poly(4-vinylphenol) (PVPh), into a multilayer system with poly(allylamine hydrochloride) (PAH) from a dilute aqueous media. Film growth was monitored using absorption spectroscopy and revealed a clear linear trend in film thickness. The surface morphology, thickness, and swelling of the multilayer films systems were examined using atomic force microscopy (AFM). Film thickness greatly depended upon the pH of the polymer precursor solutions; 50-layer systems created at pH 12.5 and 11.0 were 8.2 and 246.6 nm thick, respectively, a difference of over 2900%. This is the first report on the incorporation of PVPh into a multilayer system from an aqueous media.     

Determination of the laterally homogeneous barrier height of palladium Schottky barrier diodes on n-Ge (1 1 1)

We have studied the experimental linear relationship between barrier heights and ideality factors for palladium (Pd) on bulk-grown (1 1 1) Sb-doped n-type germanium (Ge) metal-semiconductor structures with a doping density of about 2.5×10¹⁵ cm^?3. The Pd Schottky contacts were fabricated by vacuum resistive evaporation. The electrical analysis of the contacts was investigated by means of current–voltage (I–V) and capacitance–voltage (C–V) measurements at a temperature of 296 K. The effective barrier heights from I–V characteristics varied from 0.492 to 0.550 eV, the ideality factor n varied from 1.140 to 1.950, and from reverse bias capacitance–voltage (C^?2–V) characteristics the barrier height varied from 0.427 to 0.509 eV. The lateral homogenous barrier height value of 0.558 eV for the contacts was obtained from the linear relationship between experimental barrier heights and ideality factors. Furthermore the experimental barrier height distribution obtained from I–V and (C^?2?V) characteristics were fitted by Gaussian distribution function, and their mean values were found to be 0.529 and 0.463 eV, respectively.     

Psoralen photochemotherapy

Psoralens and sunlight have been used by the Egyptians and Indians for hundreds of years for treating vitiligo. The combination of oral psoralens and artificial ultraviolet A (PUVA) therapy was approved for managing severe psoriasis by the Food and Drug Administration in 1982. Since then, PUVA therapy has been an effective modality for treating many cutaneous conditions (psoriasis, atopic dermatitis, vitiligo, and mycosis fungoides). However, proper knowledge and administration of PUVA therapy are vital to treatment success and reducing side effects.