In-situ biosynthesized plant exudate gums­silver nanocomposites as corrosion inhibitors for mild steel in hydrochloric acid medium.

Natural gums due to availability, multifunctionality, and nontoxicity are multifaceted in application. In corrosion inhibition applications, their performance, in unmodified form is unsatisfactory because of high hydration rate, solubility issues, algal and microbial contamination, as well as thermal instability. This work attempts to enhance the inhibitive performance of Berlinia grandiflora (BEG) and cashew (CEG) exudate gums through various modification approaches. The potential of biogenic BEG and CEG gums-silver (Ag) nanocomposites (NCPs) for corrosion inhibition of mild steel in 1 M HCl is studied. The nanocomposites were characterized using the FTIR, UV-vis, and TEM techniques. The corrosion studies through the gravimetric and electrochemical (PDP, EIS, LPR, and EFM) analyses reveal moderate inhibition performance by the nanocomposites. Furthermore, the PDP results reveal that both inhibitors are mixed-type with maximum corrosion inhibition efficiencies (IEs) of 61.2 % and 54.2 % for BEG-Ag NCP and CEG-Ag NCP, respectively at an optimum concentration of 1.0 %. Modification of these inhibitors with iodide ion (KI) significantly increased the IE values to 90.1 % and 88.5 % for BEG-Ag NCP and CEG-Ag NCP at the same concentration. Surface observation of the uninhibited and inhibited steel samples using SEM/EDAX, 3D Surface profilometer, and AFM affirm that the modified nanocomposites are highly effective.

An appraisal of the utilization of natural gums as corrosion inhibitors: Prospects, challenges, and future perspectives.

Natural gums are macro compounds containing monosaccharide (sugar) units bonded by glycosidic to form long polymeric sugar chains of considerably high molecular weight. Natural gums are multifaceted in applications with the main areas being the food and pharmaceutical industries. The recent research interest in corrosion inhibitors is considering natural gums because of their abundance and ecological compatibility. Hence, this review takes a look at the use of natural gums in pure and modified forms in metals protection. The review establishes that the corrosion-protecting ability of natural gums has a direct connotation with their macromolecular weights, chemical composition, and molecular and electronic structures. Immersion duration and temperature are other factors found to affect the inhibition performance of natural gums considerably. The inhibition of natural gums in pure form is found not to be excellent due to their high hydration rate, algal and microbial contamination, solubility that depends on pH, and thermal instability. Common modification techniques adopted by corrosion inhibitor scientists are copolymerization, mixing with chemicals to induce synergism, crosslinking, and insertion of inorganic nanomaterials into the polymer matrix. Infusion of biosynthesized nanoparticles approach towards enhancing the corrosion inhibition efficiency of natural gums is recommended for future studies because of the unique characteristics of nanoparticles.

A rationale for cone beam CT with extended longitudinal field-of-view in image guided adaptive radiotherapy.

PURPOSE: To investigate the efficacy of using cone beam CT with extended longitudinal field-of-view (CBCTeLFOV) for image guided adaptive radiotherapy (IGART). METHODS: The protocol acquires two CBCT scans with a linear translation of treatment couch in the patient plane, allowing a 1 cm penumbral overlap (i.e. cone beam abutment) and fused as a single DICOM set (CBCTeLFOV) using a custom-developed software script (coded in MatLab®) for extended localization. Systemic validation was performed to evaluate the geometric and Hounsfield Units accuracy at the overlapping regions of the CBCTeLFOV using a Catphan®-504 phantom. Two case studies were used to illustrate the CBCTeLFOV-based IGART workflow in terms of dosimetric and clinical perspectives. Segmentation accuracy/association between repeat CT (re-CT) and CBCTeLFOV was evaluated. Moreover, the efficacy of the CBCTeLFOV image data in deformable registration was also described. RESULTS: Slice geometry, spatial resolution, line profiles and HU accuracy in the overlapping regions of the CBCTeLFOV yielded identical results when compared with reference CBCT. In patient studies, the dice-similarity-coefficient evaluation showed a good association (>0.9) between re-CT and CBCTeLFOV. Dosimetric analysis of the CBCTeLFOV-based adaptive re-plans showed excellent agreement with re-CT based re-plans. Moreover, a similar and consistent pattern of results was also observed using deformed image data (initial planning CT deformed to CBCTeLFOV) with extended longitudinal projection and the same frame-of-reference as that of the CBCTeLFOV. CONCLUSION: Utilization of CBCTeLFOV proves to be clinically appropriate and enables accurate prediction of geometric and dosimetric consequences within the planned course of treatment. The ability to compute CBCTeLFOV-based treatment plans equivalent to re-CT promises a potential improvement in IGART practice.

Lymphoma and lymphoid leukemia incidence in Florida children: ethnic and racial distribution.

BACKGROUND: Incidence reports for pediatric lymphoma and lymphoid leukemia in Hispanic subpopulations in the United States are rare. The authors hypothesized that Florida's Hispanic children would have higher risks of lymphoma and lymphoid leukemia compared with non-Hispanic white children. METHODS: All cases of lymphoid leukemia, Hodgkin, non-Hodgkin, and Burkitt lymphoma (SEER International Classification of Diseases for Oncology codes) in children (< 15 years) in the Florida Cancer Data System (FCDS) from 1985 to 1997 were studied. Cases were classified as: 1) white, 2) Hispanic, or 3) black, and stratified by age. Age-adjusted rates for the three race-ethnic groups were calculated. Rates for Hispanics and blacks were compared with whites as standardized rate ratios (SRR) with 95% confidence intervals. RESULTS: Seven hundred thirty-one incident cases of pediatric lymphoma and 1231 cases of lymphoid leukemia were identified during the study period. For children with lymphoma, the SRR for Hispanics was 1.32 (95% CI, 1.20-1.44), and for blacks, the SRR was 0.68 (95% CI, 0.63-0.72. For lymphoid leukemia, the SRR for Hispanics was 1.29 (95% CI, 1.28-1.30), and for blacks, the SRR was 0.55 (95% CI, 0.54-0.56). Similar rates were found for the Hodgkin and non-Hodgkin subgroups. CONCLUSIONS: Incidences of Hodgkin and non-Hodgkin lymphoma were significantly higher in Florida's Hispanic children, with 30% increased relative risks, compared with whites. Black children had significantly decreased incidences and risk. Results for lymphoid leukemia were similar. Incidence of lymphoma in Florida's Hispanic children (primarily Cuban and Central American origin) differed from similar reports from Texas and California, where Hispanics are primarily of Mexican origin.

Comparison of the effect of various chemical peeling agents in a mini-pig model.

BACKGROUND: With the advent of newer chemical peels, there is now a wide range of peeling agents that can be applied on specific patients. OBJECTIVE: The purpose of this study was to closely examine the more common chemical peeling agents at different concentrations. METHODS: The study methods were carried out by thoroughly cleansing the skin surface with acetone. Different concentrations of the chemical peels were applied on different skin areas (2 x 2 cm each) and left on the skin for 15 minutes: phenol-Bakers, 25%, 50%, 75%, 88%; trichloroacetic acid, 25%, 50%, 75%; glycolic acid, 50%, 70%; and pyruvic acid, 50%, 100%. Serial biopsies were taken from each peeling site at 1, 7, and 21 days post-peel. Biopsies were then evaluated for epidermal changes, inflammation, and collagen deposition. RESULTS: The results show that Bakers phenol peel caused the most inflammation and nonspecific reaction, and in addition, a proportionate amount of new collagen deposition. Plus, increasing concentrations of phenol and TCA caused increasing amount of epidermal sloughing and inflammation after 1 day post-peel. The extent of reaction from the phenol and TCA was directly proportional to the collagen deposition at 21 days. CONCLUSIONS: The glycolic acid and pyruvic acid caused minimal nonspecific reaction. However, the collagen deposition caused by the glycolic acid and pyruvic acid was disproportionately increased suggesting a direct stimulatory effect by the two agents.

Review of day-hospital provision in psychogeriatrics.

This paper presents an overview of the current provision of day hospitals for the elderly mentally ill. By reviewing available literature the author attempts to answer a series of questions--Why is there a need for the psychogeriatric day hospital? What are the aims of those who run them? Who attends? What do they do all day? How do they get there? Who works in the day hospital? Is the service fulfilling its function? The paper ends with a consideration of how such day services may best be used in the future, and suggests that day hospitals may offer a most effective service to those elderly people with active support in the community. For this group of patients, maintenance for as long as possible within the community may be achieved through early assessment, diagnosis, treatment and rehabilitation, coupled with regular respite for the caregiver, and the day hospital provides an ideal setting for such a programme.