Processing laser ablated plasmonic nanoparticle aerosols with nonthermal dielectric barrier discharge jets of argon and helium and plasma induced effects.

Dielectric-barrier-discharge (DBD) plasma jets provide viable state-of-the-art nonthermal processes for a wide range of nanomaterials including particle transport and deposition. We report the interaction of argon and helium plasma jets with the particle aerosol, produced by ns laser ablation of a silver target and subsequently their transport for deposition on a distant substrate. The nanofeatures and functionality of the nanoparticles, entrained and deposited with the two plasma jets were compared using high-resolution electron microscopy, helium ion microscopy, scanning electron microscopy, ultraviolet-visible spectroscopy, and in terms of the SERS effect. The plasma jet facilitates the transport of the particle aerosol under the upshot of plasma ionic wind, caused by the high electric field in the plasma. Compared to the helium plasma jet, the argon plasma jet leads to a relatively large particle deposition and promotes the formation of aggregates. The helium plasma jet enabled the deposition of spatially well dispersed particles. In both cases, the deposited particle was crystalline and plasmonic active. The plasma-driven altered morphology, expedient particle transport, and formation of agglomerates or spatially well dispersed particles are explained in plasma-induced ionic-wind, and dusty plasma framework. The findings are novel and interesting from the perspective of plasma-surface deposition, surface nanoengineering, and nanomaterial processing for applications in sensing, catalysis, surgical tools, futuristic coating technology, and heat-sensible biological activities.

Detection and Quantification of Precious Elements in Astrophyllite Mineral by Optical Spectroscopy.

With many advantages over well-established methods, laser induced breakdown spectroscopy (LIBS) has emerged as a useful analytical technique for the compositional analysis of multi-elemental geological materials. In this study, LIBS was employed for qualitative and quantitative analysis of a rare mineral, astrophyllite, bearing precious elements of industrial and technological interest. The experiment was carried out using second harmonic generation of Nd:YAG laser of pulse width 5 ns and repetition rate of 10 Hz. Microplasma was produced by focusing laser beam on an astrophyllite target, and optical emissions from the generated plasma were recorded in the spectral range of 200-720 nm with the help of a LIBS2000+ detection system. On analyzing the optical spectra, existence of 15 elements in astrophyllite target were revealed. These elements include: Ti, W, Ag, Al, Ba, Ca, Cr, Cu, Fe, Li, Mg, Na, Ni, Si and H. For quantification, calibration-free method was used. Only ten elements, namely Ti, W, Fe, Cr, Cu, Ca, Mg, Ni, Si and Al, were quantified with relative weight concentrations of 55.39%, 18.79%, 18.30%, 4.05%, 2.66, 0.43%, 0.18%, 0.12%, 0.06% and 0.02%, respectively. To benchmark these results, XRF analysis was performed, which confirmed the presence of all the elements detected in the optical spectrum of the sample, except for Na, Li, and H. The concentrations of these ten elements as measured by XRF were in reasonable agreement, especially for the major elements. The presence of a significant amount of Ti and W in an astrophyllite sample, found in Pakistan, highlights the economic value of this mineral. This study may be of further interest in commissioning LIBS technology for exploration of minerals in the region.

Theoretical-Computational Study of Atmospheric DBD Plasma and Its Utility for Nanoscale Biocompatible Plasmonic Coating.

In this study, time-dependent, one-dimensional modeling of a surface dielectric barrier discharge (SDBD) device, driven by a sinusoidal voltage of amplitude 1-3 kV at 20 kHz, in argon is described. An SDBD device with two Cu-stripe electrodes, covered by the quartz dielectric and with the discharge gap of 20 × 10-3 m, was assumed, and the time-dependent, one-dimensional discharge parameters were simulated versus time across the plasma gap. The plasma device simulated in the given arrangement was constructed and used for biocompatible antibacterial/antimicrobial coating of plasmonic particle aerosol and compared with the coating strategy of the DBD plasma jet. Simulation results showed discharge consists of an electrical breakdown, occurring in each half-cycle of the AC voltage with an electron density of 1.4 × 1010 cm-3 and electric field strength of 4.5 × 105 Vm-1. With SDBD, the surface coating comprises spatially distributed particles of mean size 29 (11) nm, while with argon plasma jet, the nanoparticles are aggregated in clusters that are three times larger in size. Both coatings are crystalline and exhibit plasmonic features in the visible spectral region. It is expected that the particle aerosols are collected under the ionic wind, induced by the plasma electric fields, and it is assumed that this follows the dominant charging mechanisms of ions diffusion. The cold plasma strategy is appealing in a sense; it opens new venues at the nanoscale to deal with biomedical and surgical devices in a flexible processing environment.

Pattern of dyslipidemia in adult diabetic subjects in the community hospital of district Swat.

BACKGROUND: The incidence of diabetes is growing at dramatic rates around the word and its complications are associated with significant health and financial burdens, warranting strong and comprehensive prevention efforts. The objective of the present study was to evaluate the pattern of dyslipidemia in the adult diabetic patients in Saidu Teaching Hospital, Saidu Sharif, Swat. METHODS: The study comprised of 100 subjects, 50 subjects with diabetes and 50 (non-diabetic) controls. The serum Cholesterol, Triglycerides, High-density Lipoprotein-Cholesterol (HDL-C) and Low-density Lipoprotein-Cholesterol (LDL-C), blood sugar (random and fasting), blood pressure (systolic and diastolic) of Diabetic subjects were compared with Control subjects. RESULTS: Diabetic subjects had high mean value of Triglycerides and LDL-C (but statistically nonsignificant), low level of HDL-C (statistically highly significant) and high blood pressure as compared to Control subjects. CONCLUSION: Dyslipidemia is a potent predictor of cardiovascular morbidity and mortality in diabetic patients.

Screening of 110 cirrhotic patients for hepatitis B and C at Saidu Teaching Hospital Saidu Sharif Swat.

BACKGROUND: Cirrhosis liver is amongst the commonest clinical conditions in Pakistan. Besides other causes, it is mostly related to previous viral infection, in this part of the world. The main objective of this study was to find the frequency of HBsAg and anti HCV in cirrhotic patients of Swat district. METHODS: This Prospective Study was conducted in the Medical unit of Saidu Teaching Hospital, Saidu Sharif from January 2006 to December 2006. One hundred and ten Cirrhotic Patients, 62 Male and 48 Female aged from 14 to 75 years were included in this study. Sera were tested by 3rd generation Elisa method. RESULTS: Fifty-nine out of 110 (53.6%) patients were positive for anti HCV antibodies. Twenty-four (21.81%) Patients were positive for HBsAg. Eleven (10%) patients were positive for both HBsAg and anti HCV anti bodies. Sixteen (14.54%) were negative for both sero maker of hepatitis B and C. CONCLUSION: It is evident from this study that Hepatitis C, is a leading cause of cirrhosis in District Swat followed by HBV. Both the viruses account for at least three fourths of the total Cirrhotic.

Comparison of frequency of hepatitis B and hepatitis C in pregnant women in urban and rural area of district Swat.

OBJECTIVES: This retrospective analytical study was carried out to observe the frequency of Hepatitis B and Hepatitis C among the pregnant women of Swat. METHODS: The study was carried out from January 2008 to December 2008. It was a retrospective study based on review of records of pregnant women admitted to Labour Room of Obstetrics/Gynaecology Unit, Saidu Teaching Hospital, Swat. Patients were screened for Hepatitis B and C by Immuno Chromatographic Technique (ICT) device. The findings were recorded on proforma and analysed. Those found positive on screening test were confirmed by ELISA. RESULTS: Total number of patients screened was 5607. The frequency of Hepatitis B and C (Combined) was 223 (3.98%), out of which 77 (1.37%) were HBsAg positive, 141 (2.52%) were anti HCV positive and 5 (0.09%) were both HBsAg and anti HCV positive. The frequency of Hepatitis B amongst age groups 14-19, 20-29, 30-39 and 40-49 years were 2/77, 33/77, 40/77, and 2/77) respectively. The frequency of Hepatitis C amongst age groups 14-19, 20-29, 30-39 and 40-49 years was 4/141, 59/141, 67/141 and 11/141 respectively. The frequency of Hepatitis B and C in multigravida was 41/77, 67/141, in grand multigravida it was 20/77, 43/141 and in primigravida it was 16/77, 31/141 respectively. The frequency of Hepatitis B and Hepatitis C amongst urban and rural population was 32 (39.02%) and 50 (60.98%); and 40 (27.40%) and 106 (72.60%) respectively. The frequency of Hepatitis B and C (Combined) in urban, rural population were 72 (31.58 %) and 156 (68.15%) respectively. CONCLUSION: HBsAg and HCV was common infections in pregnant women of Swat. Therefore, every pregnant woman undergoing delivery and/or any other surgical procedure must be screened for Hepatitis B and Hepatitis C.

Oesophageal cancer in northern areas of Pakistan.

BACKGROUND: Oesophageal carcinoma is the leading cause of death from cancers. Most of the oesophageal carcinomas are either squamous cell carcinomas or adeno-carcinomas. The cervical oesophagus is an uncommon site of the disease. There is an increase of 15-20 percent mortality rate over the past two to three decades, during which time the histologic pattern of the disease has also changed significantly. OBJECTIVE: The objective of this study was to see the incidence of oesophageal carcinoma in different sex and age groups, in the northern areas of Pakistan. METHOD: This was a retrospective study over a period of 7 years which was designed to assess age and sex incidence for oesophageal carcinoma in northern areas of Pakistan. A total of 69 already diagnosed carcinomas of the oesophagus were included in the study, all these cases were from Malakand Division of northern Pakistan. All specimens were stained and examined microscopy. The demography of the disease and type of carcinoma were evaluated. RESULTS: Out of 69 diagnosed cases of oesophageal carcinomas, squamous cell carcinoma was the found in 64 (92.5%) while adenocarcinoma was seen in 5 (7.5%) cases. Out of 64 squamous cell carcinomas, moderately differentiated carcinomas were the most common 34 (49.2%). CONCLUSION: Most of the oesophageal carcinomas were squamous cell carcinomas and were mostly biopsied from the lower 1/3rd of the oesophagus. The mean age of patients was 42 years in males (M) and 53 years in females (F). F:M was 1:3. All patient presented in advanced stage with dysphagic symptoms. No in situ or mucosal carcinoma was identified in this study. Radiological assessment also showed late stages of the disease.

Frequency of ABO and Rhesus blood groups in District Swat, Pakistan.

BACKGROUND: Up till now about 400 red cells antigen have been identified. The majority are inherited by Mendelian Fashion. The ABO blood group system was first to be identified and RH blood group system was the 4th one, both are most important for blood transfusion purposes. This study is conducted to determine the frequency of ABO and Rhesus (Rh) blood groups in District Swat, NWFP, Pakistan. It is a cross sectional prospective study and was conducted at Saidu Teaching Hospital district Swat, over a period of one year. (1st Jan. 2007 to 31st Dec, 2007). METHODS: A total of 22897 subjects were included in this study. Patients were collected from different wards of Saidu Teaching Hospital while the donors from common population. From each subject blood was collected, ABO and Rh blood grouping were carried out by tile method using commercially prepared anti sera. The frequency of each type was calculated. RESULTS: Out of 22897 subjects 17141 (74.86%) were male subjects and 5756 (25.140%) were female. Out of 17141 male subjects 15597 (90.99%) and out of 5756 female subjects 5040 (87.56%) were found to be Rh-positive. The frequency of Rh-negative group in male subjects were (9.01%) where as in female subjects were (12.22%). The frequency of A, B, O and AB groups in Rh-positive male subjects were 25.63%, 29.54%, 26.04% and 9.78%, amongst female subjects, it was 24.53%, 28.06%, 25.54% and 9.43% respectively. In Rh-negative male subjects the frequency of A, B, O and AB is 2.25%, 2.88%, 3.01% and 0.88%, while amongst females it is 3.54%, 4.24%, 3.74% and 0.92% respectively. CONCLUSION: It is concluded from this study that frequency of Rh-positive blood group is B, O, A, and AB in both gender. Where as the most common Rh-negative in male and female subjects are O, B, A, AB, and B, O, A, and AB respectively.

Comparison of plasma viscosity and fibrinogen concentration in hypertensive and normotensive diabetics.

BACKGROUND: Body weight, body mass index, fibrinogen concentration and relative plasma viscosity can contribute to the development of hypertension in diabetics. This study compares body weight, body mass index, fibrinogen concentration and relative plasma viscosity between hypertensive diabetics, normotensive diabetics and healthy controls. METHODS: The present study was carried out on normotensive and hypertensive diabetics taken from medical OPD of Saidu group of teaching hospitals, Swat. A group of healthy male subjects between 30-60 years of age from the staff members of Saidu Medical College, Swat was also included. Each group comprised of 35 subjects. Systolic and diastolic blood pressures, body weight, height, body mass index, fibrinogen concentration and relative plasma viscosity were measured and compared. RESULTS: Body weight, body mass index, fibrinogen concentration and relative plasma viscosity were all significantly more in hypertensive diabetics than normotensive diabetics and healthy control subjects. CONCLUSION: The onset of the complications is different in the two groups of diabetics (hypertensive and normotensive), earlier in hypertensive diabetics and delayed in normotensive diabetics.

Effect of tamoxifen on pituitary vasopressin level.

BACKGROUND: Estrogens modulate the release of Arginine Vasopressin (AVP). There is an increased level of AVP in plasma and pituitary under osterogen hormones. METHODS: Ten rats were experimental and ten were controls. The ten experimental rats were injected tamoxifen daily subcutaneously for three days in does of 1 mg/kg body weight in 0.1 ml vegetable oil base. The ten control rats were given 0.1 ml of vegetable oil vehicle only subcutaneously. On the morning of the fourth day all the twenty rats were decapitated. Blood was centrifuged at 2500 rev/min for 15 min at 4 degrees C. Plasma was stored at -20 degrees C for assay of AVP. Pituitary gland was removed and homogenized in a test tube containing 1 ml of 0.2 molar acetic acid & stored at -20 degrees C for analysis of pituitary AVP. Uteri of all rats were removed by careful dissection & weighed. RESULTS: Uterine weight and plasma AVP levels were decreased but the pituitary AVP level was unaffected. CONCLUSION: Under Tamoxifen (anti-estrogen) effect the plasma vasopressin decreased but the level in the posterior was not affected. The effect of osterogen on Hypothalamo Pituitary axis (HPA is measurable in the hypothalamus therefore probably anti-oestrogenic effect would operate more at hypothalamic level rather than posterior pituitary. This needs further investigation at the Hypothalamus level.