Investigating the Z-scan technique for quantifying circulating cell-free DNA (ccfDNA) extracted from blood plasma as a potential biomarker for various cancers.

The Z-scan technique is a nonlinear optical method that has found applications in characterizing various materials, particularly those exhibiting nonlinear optical response (NLOR). This study applies the continuous wave (CW) Z-scan technique to examine the NLOR in terms of the nonlinear optical phase shifts(ΔΦ0) exhibited by the ccfDNA extracted from blood plasma samples collected from a group constituting 30 cancer-diagnosed patients and another group constituting 30 non-diagnosed individuals. The cancer group exhibited significantly higherΔΦ0versus incident power slopes compared to the non-cancer group (0.34 versus 0.12) providing a clear distinction between the two groups. The receiver operating characteristic (ROC) curve analysis of the results indicates a clear separation between cancer and non-cancer groups, along with a 94% accuracy rate of the data. The Z-scan results are corroborated by spectrophotometric analysis, revealing a consistent trend in the concentration values of ccfDNA samples extracted from both cancerous and non-cancerous samples, measuring 3.24 and 1.41 respectively. Additionally, more sensitive fluorometric analyses of the respective samples demonstrate significantly higher concentrations of ccfDNA in the cancer group, further affirming the correlation with the Z-scan results. The study suggests that the Z-scan technique holds promise as an effective method for cancer detection, potentially contributing to improved oncology diagnosis and prognosis in the future.

Low adhesion, non-wetting phosphonate self-assembled monolayer films formed on copper oxide surfaces.

Self-assembled monolayer (SAM) films have been formed on oxidized copper (Cu) substrates by reaction with 1H,1H,2H,2H-perfluorodecylphosphonic acid (PFDP), octadecylphosphonic acid (ODP), decylphosphonic acid (DP), and octylphosphonic acid (OP) and then investigated by X-ray photoelectron spectroscopy (XPS), contact angle measurement (CAM), and atomic force microscopy (AFM). The presence of alkyl phosphonate molecules, PFDP, ODP, DP, and OP, on Cu were confirmed by CAM and XPS analysis. No alkyl phosphonate molecules were seen by XPS on unmodified Cu as a control. The PFDP/Cu and ODP/Cu SAMs were found to be very hydrophobic having water sessile drop static contact angles of more than 140 degrees , while DP/Cu and OP/Cu have contact angles of 119 degrees and 76 degrees , respectively. PFDP/Cu, ODP/Cu, DP/Cu, and OP/Cu SAMs were studied by friction force microscopy, a derivative of AFM, to better understand their micro/nanotribological properties. PFDP/Cu, ODP/Cu, and DP/Cu had comparable adhesive force, which is much lower than that for unmodified Cu. ODP/Cu had the lowest friction coefficient followed by PFDP/Cu, DP/Cu, and OP/Cu while unmodified Cu had the highest. XPS data gives some indication that a bidentate bond forms between the alkyl phosphonate molecules and the oxidized Cu surface. Hydrophobic phosphonate SAMs could be useful as corrosion inhibitors in micro/nanoelectronic devices and/or as promoters for anti-wetting, low adhesion surfaces.

Risk Factors for Anaemia in Pregnancy in Rural KwaZulu-Natal - South Africa: Implication for Health Education and Health Promotion

Background: Anaemia in pregnancy is a major public health problem in developing countries. It is associated with an increased risk of maternal and perinatal morbidity and mortality. A high rate of anaemia in pregnancy in the rural population of KwaZulu-Natal (30according to national and 57according to the World Health Organization [WHO] definition of anaemia in pregnancy) is observed. The risk factors for anaemia; particularly during pregnancy; are multiple and complex and their relative contributions are known to vary by geographic areas and by seasons. In order to design an intervention for treatment and prevention of anaemia in pregnancy; studies to assess the aetiological factors are necessary. The aim of this study was to evaluate the strength of association between intestinal helminthiasis; urinary schistosomiasis and HIV infection on anaemia in pregnancy. Methods: A retrospective case-control study design was used in a rural district hospital of South Africa. A total of 300 pregnant women; 100 of them with anaemia (haemoglobin less than 10 gm/dL according to the national definition of anaemia in pregnancy) referred as cases and 200 controls were studied from Empangeni Hospital. Both cases and controls were matched for age; parity and gestational age. Data were collected from the antenatal clinic and prevention of mother-to-child transmission of HIV (PMTCT) programme registers for cases and controls at their booking visit during the months of May; June and July of 2004. Univariate and multiple logistic regression were performed to analyse the data. Results: Of the cases; 48and 1among the controls had intestinal helminthiasis; resulting in the odds ratio of 42 (p = 0;000 and 95CI 9;96 -176.59). The risk of anaemia was related to urinary schistosomiasis; as 27of the cases compared to 1of controls was found with anaemia. The odds ratio was 12 (p = 0;000 and 95CI 3.58 - 41.02). These parasitic infestations are known to cause chronic haemorrhage and iron deficiency resulting in the development of anaemia in pregnancy. Transmissions of intestinal parasitic infestation occur through the faecal-oral route. Personal hygiene and other environmental factors are therefore an important factor for the transmission of the disease. To reduce the transmission of faecaloral diseases (e.g. intestinal helminthiasis and urinary schistosomiasis) key interventions recommended are: 1) safe disposal of human excreta; 2) hand-washing practices with soap after defecation; and 3) maintenance of drinking water free from faecal contamination. Similarly; HIV infection increased the chance of developing anaemia in pregnancy twofold as HIV infection was more common among cases (56) than among controls (37); resulting in an odds ratio of 2.11 (p = 0;003 and 95CI 1.123 - 3.21). The prevention of HIV infection and transmission can be achieved through the improvement of knowledge of these conditions. These can be achieved through health education and health promotion. Conclusion: These findings confirm and conform to other studies on the association between anaemia in pregnancy and parasitic and HIV infections. Antenatal care should promote de-worming and education on personal hygiene and HIV (risk factors; mode of transmission; etc.). The provision of safe water supply and toilet facilities for the rural communities should be considered urgently to prevent and promote better health for all; including pregnant women

Knowledge of and Attitude Towards Cervical Cancer among Female University Students in South Africa

The objectives of this descriptive cross-sectional study were to assess the knowledge of the risk factors associated with; and detection methods of cervical cancer among female undergraduate students at Mangosuthu University of Technology. A total of 389 students were selected by stratified random sampling techniques. Participants' mean age was 20 years (SD=2). Results indicated that 51.2students were currently involved in a sexual relationship; with 19.2reporting two or more sexual partners in the past year. Less than half (42.9) of the participants had heard of cervical cancer and of these; 26 (15.6) did not know any risk factors for cervical cancer; while 96 (58.6) of 164 participants who knew of risk factors; did not know that cervical cancer is preventable. One-hundred and sixty-three (41.9) participants had heard about the Pap smear test. That the Pap smear test is used for detection or prevention of cervical cancer; was known to 62 (38) of the respondents. Only 16 (9.8) participants had had a Pap smear test. Among those who knew about the Pap smear test (n=136); 86 respondents did not have the test done mainly because of personal factors such as fear of the procedure; cultural or religious reasons; and were not ill (61.1). Findings suggest low level of knowledge on cervical cancer and its risk factors and detection method among these female university students. The university should thus concentrate on developing policies on health education and promotion; particularly targeting preventable health conditions; eg. cervical cancer and strategies to prevent transmission of the human papillomavirus

Evaluation of Cervical Cancer Screening Program at a Rural Community of South Africa

Objective: Cervical cancer is a leading cause of deaths among women worldwide. But the condition is preventable through regular screening of women those are 'at risk' for abnormal changes in the cervix and treating them who have positive results. Although screening facilities are available in South Africa; the incidence and mortality from cervical cancer remains very high and many women present health facilities with late stage diseases. Purpose of the study is to determine the baseline information on knowledge and practices on risk factors for cervical cancer and Pap smear and to design an intervention to improve Pap smear uptake. Methods: A cross-sectional population based descriptive study was undertaken at a rural community of South Africa targeting women 30 years and over. The assessment was performed by means of a questionnaire survey. Outcome measures were percentage of women with the knowledge on risk factors for cervical cancer and use of Pap smear test and had undertaken Pap smear test. Binary logistic regression analysis was carried out to identify possible predictors of Pap smear test undertaken. A total of 611 women (random samples) were recruited from the selected households. Results: The mean age of the sample was 43 years and 54of them had no education. Only 6knew all and 65knew any one of the risk factors of cervical cancer whereas less than half (49) of them knew that Pap smear is used for prevention of cervical cancer. Only 43respondents received information on Pap smear from health care workers. Among all the respondents only 18(95CI; 15-21) had ever done Pap smear test. Conclusions: This study showed low uptake of Pap smear test and low level of knowledge on prevention of cervical cancer and risk factors thus warrants urgent extensive health education program for this rural communities

Chemical stability of nonwetting, low adhesion self-assembled monolayer films formed by perfluoroalkylsilanization of copper.

A self-assembled monolayer (SAM) has been produced by reaction of 1H,1H,2H,2H-perfluorodecyldimethylchlorosilane (PFMS) with an oxidized copper (Cu) substrate and investigated by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), friction force microscopy (FFM), a derivative of AFM, and contact angle measurement. FFM showed a significant reduction in the adhesive force and friction coefficient of PFMS modified Cu (PFMS/Cu) compared to unmodified Cu. The perfluoroalkyl SAM on Cu is found to be extremely hydrophobic, yielding sessile drop static contact angles of more than 130 degrees for pure water and a "surface energy" (which is proportional to the Zisman critical surface tension for a Cu surface with 0 rms roughness) of 14.5 mJm2(nMm). Treatment by exposure to harsh conditions showed that PFMS/Cu SAM can withstand boiling nitric acid (pH=1.8), boiling water, and warm sodium hydroxide (pH=12, 60 degrees C) solutions for at least 30 min. Furthermore, no SAM degradation was observed when PFMS/Cu was exposed to warm nitric acid solution for up to 70 min at 60 degrees C or 50 min at 80 degrees C. Extremely hydrophobic (low surface energy) and stable PFMS/Cu SAMs could be useful as corrosion inhibitors in micro/nanoelectronic devices and/or as promoters for antiwetting, low adhesion surfaces or dropwise condensation on heat exchange surfaces.

Injury Profile in KwaZulu-Natal; South Africa: Implications for Prevention

Background: Prevention and control of injuries require generating relevant information on the magnitude; characteristics and determinants of injuries. Objective: The objective of this study was to describe the characteristics of injuries and predict the severity of injury with other variables. Design: A cross - sectional descriptive study was conducted at the hospitals of KwaZulu - Natal. Information was gathered from a total of 428 injured patients randomly selected from hospital attendances. Multivariate logistic regression analysis was performed to identify the risk factors for severity of injury. Results: Over 60of injury victims were below the age of 30 years. The economically active group (21 - 60 years) also constituted about 60of injury victims. Over half of the victims reported that the scene of incidence was private house; yard and road. One fifth was transport related injury whereas majority was violence (50). Unintentional injury was 28.8. Most of the injuries were minor (42.3) to moderate (41.1) in severity. Odds Ratio for alcohol related violence was 11. Conclusion: In order to reduce injuries appropriate multisectoral interventions; broader policies and strategies; regulating transport and alcohol use; routine testing of alcohol to identify the problem-drinkers for rehabilitation. Interventions should also include health education and health promotion and law enforcement

Alkylphosphonate modified aluminum oxide surfaces.

The surface properties of aluminum, such as chemical composition, roughness, friction, adhesion, and wear, can play an important role in the performance of micro-/nano-electromechanical systems, e.g., digital micromirror devices. Aluminum substrates chemically reacted with octadecylphosphonic acid (ODP/Al), decylphosphonic acid (DP/Al), and octylphosphonic acid (OP/Al) have been investigated and characterized by X-ray photoelectron spectroscopy (XPS), contact angle measurements, and atomic force microscopy (AFM). XPS analysis confirmed the presence of alkylphosphonate molecules on ODP/Al, DP/Al, and OP/Al. No phosphonates were found on bare Al as a control. The sessile drop static contact angle of pure water on ODP/Al and DP/Al was typically more than 115 degrees and on OP/Al typically less than 105 degrees indicating that all phosphonic acid reacted Al samples were highly hydrophobic. The root-mean-square surface roughness for ODP/Al, DP/Al, OP/Al, and bare Al was less than 15 nm as determined by AFM. The surface energy for ODP/Al and DP/Al was determined to be approximately 21 and 22 mJ/m2, respectively, by the Zisman plot method, compared to 25 mJ/m2 for OP/Al. ODP/Al and OP/Al were studied by friction force microscopy, a derivative of AFM, to better understand their micro-/nano-tribological properties. ODP/Al gave the lowest coefficient of friction values while bare Al gave the highest. The adhesion forces for ODP/Al and OP/Al were comparable.

Phosphonate self-assembled monolayers on aluminum surfaces.

Substrates of aluminum (Al) deposited by physical vapor deposition onto Si substrates and then chemically reacted with perfluorodecylphosphonic acid (PFDPAlSi), decylphosphonic acid (DPAlSi), and octadecylphosphonic acid (ODPAlSi) were studied by x-ray photoelectron spectroscopy (XPS), contact angle measurements, atomic force microscopy (AFM), and friction force microscopy, a derivative of AFM, to characterize their surface chemical composition, roughness, and micro-/nanotribological properties. XPS analysis confirmed the presence of perfluorinated and nonperfluorinated alkylphosphonate molecules on the PFDPAlSi, DPAlSi, and ODPAlSi. The sessile drop static contact angle of pure water on PFDPAlSi was typically more than 130 degrees and on DPAlSi and ODPAlSi typically more than 125 degrees indicating that all phosphonic acid reacted AlSi samples were very hydrophobic. The surface roughness for PFDPAlSi, DPAlSi, ODPAlSi, and bare AlSi was approximately 35 nm as determined by AFM. The surface energy for PFDPAlSi was determined to be approximately 11 mNm by the Zisman plot method compared to 21 and 20 mNm for DPAlSi and ODPAlSi, respectively. Tribology involves the measure of lateral forces due to friction and adhesion between two surfaces. Friction, adhesion, and wear play important roles in the performance of micro-/nanoelectromechanical systems. PFDPAlSi gave the lowest adhesion and coefficient of friction values while bare AlSi gave the highest. The adhesion and coefficient of friction values for DPAlSi and ODPAlSi were comparable.

Chronic renal failure in children.

The study was carried out to see the etiology and outcome of chronic renal failure in children. It is a prospective study, carried out to evaluate all new cases of CRF in children < 15 years in nephrology unit of BSMMU from May 2000 to May 2002. Diagnosis of CRF was based on Ccr < 75 ml/min/m(2) along with other features of CRF with no evidence of recovery over ensuing three months. A total of 44 children with CRF having mean age of 8.73 3.56 years were diagnosed during study period, among them, 30 cases (68.19%) were male and 14 cases (31.81%) were female. Causes of CRF were obstructive uropathy in 24 cases (54.55%) followed by glomerular diseases in 15 cases (34.9%), hereditary disorders in 3 cases (6.81%), and reflux nephropathy in 2 cases (4.54%). At presentation, 13 (29.55%) children had mild to moderate CRF and 31 (70.45%) children had severe CRF and ESRD. Mean follow up period was 32.3 weeks. At the end of the study period, 8 patients of mild to moderate CRF were on conservative treatment, 6 patients of severe CRF and ESRD group attended for maintenance dialysis irregularly of which 3 died at hospital and rest of the patients did not attend at follow up due to financial reason or opted against IPD. In the present study, majority of the children with CRF is due to treatable obstructive uropathy; mostly PUV and most of them presented with advanced renal disease.

Comparison of two methods for estimation of soil sorption for imidacloprid and carbofuran.

Predicting the fate and transport of pesticides in soil environment is an important issue especially in understanding and modelling of the environmental behaviour of pesticides. Classical batch sorption method often has been identified as insufficient to derive the actual extent of sorption. In this study, the batch equilibrium method was compared to the centrifugation method, which can permit measurement of sorption under more natural conditions. The results of the comparison of the batch with the centrifugation method for imidacloprid and carbofuran pesticides indicate that the batch method overestimates sorption in comparison to the centrifugation method. These results are in agreement with others, which use high soil:solution ratios with batch and those that used the centrifugation method.

Natural UV-Screening Mechanisms of Norway Spruce (Picea abies [L.] Karst.) Needles.

Ultraviolet-light screening potential of Norway spruce (Picea abies [L.] Karst.) needles was investigated by UV-spectroscopic, microscopic, fluorescence spectroscopic techniques as well as by HPLC, mass spectrometry and NMR spectroscopy. Results showed four potential barriers of UV screening by Norway spruce needles: (1) UV-light screening via reflectance of UV/violet light by epidermis, (2) UV-light screening via reduction of transmission of UV light by special anatomical arrangement of the epidermal cells containing the UV-screening allomelanins as well as by the light-reflecting hyaline hypodermal cells, (3) conversion of UV light by epidermis into photosynthetically active radiation (PAR; blue and red spectral bands) via fluorescence and (4) UV-light screening by absorption of UV light by UV-screening substances contained in the epidermis, whereby the latter was found to be the most important UV-screening mechanism. Staining of needle cross sections with Naturstoffreagenz A showed the localization of bound flavonoids and its derivatives in the cell walls of the outer epidermal cell layer as revealed by confocal laser scanning microscopy. By fluorescence spectroscopy and confocal laser scanning microscopy, the conversion of UVA light into PAR in the epidermis was related to various UV-screening substances contained in the epidermis. The methanol-soluble UV-absorbing substances were found to create novel UV-screening barrier zones: UVC, >200-253 nm; UVC/UVB, >253-300/303 nm; and UVB/UVA, >300-362/368 nm in epidermis as well as in mesophyll (±vascular bundles) tissues, suggesting the protective functions of epidermis for the underlying mesophyll as well as of mesophyll for the underlying vascular bundles. The following sequence of efficiency of UV-screening barrier zones of the methanol-soluble extracts of the needle epidermis and mesophyll (± vascular bundles) for various UV-spectral bands was detected: UVC screening at less than 265 nm > UVC screening at 265-280 nm > UVB screening at 280­320 nm > UVA screening at 320­400 nm, whereby the UV screening at 280-320 nm was suggested as the most relevant barrier against enhanced UVB radiation. A blend of various UV-screening substances occurred in the methanol-soluble fractions of needle epidermis, whereby p-hydroxybenzoic acid 4-O-ß-D-glucopyranoside, picein, (+)-catechin, p-hydroxyacetophenone, benzoic acid and astragalin were identified as UVC/UVB-screening substances; picein, (+)-catechin, astringin, p-hydroxyacetophenone and astragalin(s) as UVB-screening substances and astragalin(s) as UVA/B-screening substances. Alkaline hydrolysis of methanol-insoluble epidermal cell wall fractions released p-coumaric acid, ferulic acid and as-tragalin(s) as major UVB-screening substances. Loss of vitality of Norway spruce trees (forest decline disease) led to a significant reduction of UVB (315 nm)-screening ability of methanol-soluble fractions from epidermis, mesophyll (±vascular bundles) and whole needles. The HPLC analysis showed that the loss of vitality is due to a reduction in accumulation of UVB-absorbing substances, mainly picein, (+)-catechin, isorhapontin and astragalin(s) in the epidermis of needles from the second needle year in accordance with the detected loss of UVB-screening ability. It is concluded that the natural UV-screening mechanisms of Norway spruce needles are highly complex but mainly actively mediated by the ability of methanol-soluble UV-absorbing substances to form variable UVB-AJVA-screening barrier zones and passively by the ability of epidermal cell wall-bound UV-screening substances to screen UV light, whereby in the epidermis a conversion of excess UV light into PAR takes place.

A new intermediate in the mineralization of 3,4-dichloroaniline by the white rot fungus Phanerochaete chrysosporium.

Phanerochaete chrysosporium ATCC 34541 has been reported to be unable to mineralize 3,4-dichloroaniline (DCA). However, high mineralization is now shown to occur when a fermentation temperature of 37 degrees and gassing with oxygen are used. Mineralization did not correlate with lignin peroxidase activity. The latter was high under C limitation and low under N limitation, whereas the reverse was true for mineralization. The kinetics of DCA metabolism was studied in low-N and low-C and C- and N-rich culture media by metabolite analysis and 14CO2 determination. In all cases, DCA disappeared within 2 days, and a novel highly polar conjugate termed DCAX accumulated in the growth medium. This metabolite was a dead-end product under C and N enrichment. In oxygenated low-C medium and in much higher yield in oxygenated low-N medium, DCAX was converted to DCA-succinimide and then mineralized. DCAX was purified by high-performance liquid chromatography and identified as N-(3,4-dichlorophenyl)-alpha-ketoglutaryl-delta-amide by high-performance liquid chromatography and mass spectroscopy, gas chromatography and mass spectroscopy, and nuclear magnetic resonance spectroscopy. The formation of conjugate intermediates is proposed to facilitate mineralization because the sensitive amino group of DCA needs protection so that ring cleavage rather than oligomerization can occur.