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Biomedical subjects

James H Clark

Publications and source records attributed to James H Clark.

12 recordsLinked to original sources
PubMed2006

A critique of Women's Health Initiative Studies (2002-2006).

The Women's Health Initiative Studies (WHI) were designed to examine the effects of estrogen and progestin (E+P; Prempro) and estrogen alone (Premarin) in post-menopausal women. The authors of the WHI studies and the National Heart Lung and Blood Institute (NHLBI) concluded that E+P treatment increased the risks of coronary heart disease, invasive breast cancer, stroke and venous thromboembolism. The following paper contains a reevaluation of these studies based on the graphic analysis of their tabulated data. In contrast to the conclusions reached by the WHI and the NHLBI, I conclude that treatment of post-menopausal women with estrogen and progestin (Prempro) does not increase the risks of cardiovascular disease, invasive breast cancer, stroke or venous thromboembolism. I also disagree with the claim that an increased risk of stroke existed in women treated with estrogen alone.

Journal Article↗
PubMed2006

The application of modified mesoporous silicas in liquid phase catalysis.

This review focuses on recent developments in the preparation, properties and catalytic applications of chemically modified mesoporous silicas. Over the last few years, this group of materials has been the subject of intense activity in the materials community, and many applications have been found for these fascinating materials. This non-exhaustive review aims to highlight the key features of the materials, which are relevant and important to catalysis, and illustrates their utility with a series of recent examples.

Journal Article↗
PubMed2005

Selective oxidation of sulfides to sulfoxides using 30% hydrogen peroxide catalyzed with a recoverable silica-based tungstate interphase catalyst.

Various types of aromatic and aliphatic sulfides are selectively oxidized to sulfoxides and sulfones in good to excellent yields using 30% H2O2 in the presence of catalytic amounts of a novel recoverable silica-based tungstate interphase catalyst at room temperature. The catalyst can be recovered and reused for at least eight reaction cycles under the described reaction conditions without considerable loss of reactivity. [reaction: see text]

Journal Article↗
PubMed2002

Solid acids for green chemistry.

Solid acids and especially those based on micelle-templated silicas and other mesoporous high surface area support materials are beginning to play a significant role in the greening of fine and specialty chemicals manufacturing processes. A wide range of important organic reactions can be efficiently catalyzed by these materials, which can be designed to provide different types of acidity as well as high degrees of reaction selectivity. The solid acids generally have high turnover numbers and can be easily separated from the organic components. The combination of this chemistry with innovative reaction engineering offers exciting opportunities for innovative green chemical manufacturing in the future.

Acids↗
PubMedDate not supplied

Role of sonography in pancreatic transplantation.

Despite recent advancements in surgical technique and immunosuppressive therapy, postoperative complications of pancreatic transplantation are still common. A complex spectrum of such adverse events includes graft rejection, peripancreatic fluid collections, pancreatitis, exocrine leaks, vascular thrombosis, and hemorrhage. Sonography plays a key role in the initial evaluation of the transplanted pancreas. Gray-scale sonography, duplex Doppler imaging, and sonographic guidance for percutaneous biopsy all contribute to posttransplantation evaluation and detection of sequelae. Color and power Doppler imaging offer valuable information regarding the regional vasculature and potential vascular complications. Because gray-scale sonographic findings alone are often nonspecific, several clinical criteria, including those from biochemical analysis of the urine and serum, must be reviewed with the sonographic findings to provide a thorough evaluation of the transplanted pancreas. When used in conjunction with serologic and urinary markers, the findings from sonography can help direct management options or suggest the need for further examination. Therefore, an understanding of the spectrum of complications combined with knowledge concerning the limitations of this imaging modality are essential for proper diagnosis and effective treatment.

Humans↗