Peak to average power ratio reduction in NC–OFDM systems

Non contiguous orthogonal frequency division multiplexing (NC-OFDM) is an efficient and adaptable multicarrier modulation scheme to be used in cognitive radio communications. However like OFDM, NC-OFDM also suffers from the main drawback of high peak to average power ratio (PAPR). In this paper PAPR has been reduced by employing three different trigonometric transforms. Discrete cosine transform (DCT), discrete sine transform (DST) and fractional fourier transform (FRFT) has been combined with conventional selected level mapping (SLM) technique to reduce the PAPR of both OFDM and NC-OFDM based systems. The method combines all the transforms with SLM in different ways. Transforms DCT, DST and FRFT have been applied before the SLM block or inside the SLM block before IFFT. Simulation results show the comparative analysis of all the transforms using SLM in case of both OFDM and NC-OFDM based systems

COVID-19 pandemic & skin care guidelines for health care professionals

The Novel corona virus is bringing multiple challenges for health care professionals. Skin is the biggest organ and the first line of defense against different infections and external factors. Being the front line warriors, health care professionals are susceptible to various skin conditions due to prolonged use of personal protective equipment. These adverse skin conditions are redness, irritation, itching, contact dermatitis, and aggravation of underlying skin conditions like seborrheic dermatitis and acne vulgaris. In the current global situation, the potential incidence of such adverse dermatological effects does not in any manner cause the HCPs to deviate from the strict specific precautionary hygiene rules. These skin problems are manageable with the few precautionary measures. This article explores the different skin conditions that result from personal hygiene measures and usage of protective gear and will suggest some practical advice about how to manage and protect from these different adverse skin conditions

Bilateral systematised epidermolytic epidermal nevus: A case report

Verrucous epidermal nevi (VEN) are benign congenital hamartomas consisting of keratinocytes. Histological examination mostly exhibits hyperkeratosis, acanthosis, papillomatosis and, rarely, the features of epidermolytic hyperkeratosis (EHK). We report a case of a 6-year-old boy who presented at Aga Khan University Hospital, Karachi, Pakistan with bilaterally symmetrical linear epidermal nevi following Blaschko\u27s lines and showing epidermolytic hyperkeratosis on histology. The patient was treated with topical keratolytics and emolients which led to considerable improvement. To the best of the authors\u27 knowledge, this is the first report of VEN from Pakistan

Treatment of Molluscum Contagiosum with 10% Potassium Hydroxide Solution

Background: To determine the efficacy and safety of topical 10% potassium hydroxide solution in the treatment of molluscum contagiosum (MC) .Methods: An open, prospective, non-randomized study of one year duration was conducted using 10% KOH solution to treat MC. Twenty eight patients completed the study. A total of seven appointments were planned; one baseline and six follow-up visits. 10% KOH was applied to molluscum lesions daily till the lesions resolved or till 3 months had elapsed.Results: Twenty eight patients, among which 22 were children, completed the study. The mean age of patients was 10.6 years. The total lesion count in the patients varied from 5 – 94, with the mean lesion count of 22.14 SD +_ 18.32. There was complete resolution of lesions in 20 (71.4%) of patients , 4 (14.3) had a near complete, 2 (7.1%) had partial and 2 (7.1%) patients had no improvement. 82% patients tolerated the treatment well with no side effects.Conclusion:10% KOH solution is an effective and well tolerated treatment for MC. It is less painful and cost-effective as compared to many well-established therapeutic modalities. It has the advantage of ease of application at home making it an acceptable and feasible option for the treatment of MC

Impact of acne on quality of life in young Pakistani adults and its relationship with severity: A multicenter study

Objectives: The current study aimed to determine the effect of acne vulgaris on quality of life of young adults and to assess the correlation between acne severity and impairment of quality of life (QOLI).Methods: In this multi-center cross-sectional study, 163 young adults with acne vulgaris were assessed for severity and quality of life impairment between December 2016 and May 2017 at three tertiary care hospitals. Cardiff Acne Disability Index (CADI) was used to assess the quality of life while the severity of acne measured by Global Acne Grading System (GAGS). Data were collected on standardized forms, with CADI, GAGS scores, and sociodemographic data and analyzed using SPSS version 9. The quantitative variables were presented as means, median and qualitative variables expressed as frequency and percentages. P-value ≤0.05 was considered as statistically significant.Results: Out of 163 patients enrolled in this study, the mean age was 21.6 ± 4.9 years and 124 were females and 39 males. In mild QOLI, 56 (87.5%) cases were affected with mild, 11 (13.4%) with moderate and 1 (1.5%) case had severe acne. While, in moderate QOLI, 8(12.5%) cases were of mild, 60 (73.2%) were moderate and 6 (35.3%) cases affected with severe acne. The severe impairment of QOL noted in 11 (13.4%) moderate and 10 (58.8%) severe acne cases. The relationship between sex was statistically significant, (P\u3c0.001). The result showed significant correlation between severity of acne vulgaris and the quality of life impairment of these patients (P\u3c0.001).Conclusion: This study showed significant correlation between acne vulgaris and quality of life impairment. Cardiff acne disability index has proven to be a reliable tool to assess the quality of life. It is recommended to be used routinely in dermatology clinics to provide tailored treatment to individuals because mild disease may be disproportionately distressing for patients

Frequency of depression and anxiety among patients with chronic spontaneous urticaria visiting a tertiary care hospital in Karachi, Pakistan

Objective: To determine the frequency of anxiety and depression among chronic spontaneous urticarial patients presenting at a tertiary care hospital.Methods: The prospective, cross-sectional study was conducted at the Aga Khan University Hospital, Karachi, from February to August 2015, and comprised patients diagnosed with chronic spontaneous urticaria at the dermatology clinic. All the participants were assessed for anxiety and depression using Aga Khan University-Anxiety Depression Scale. Data was collected in face-to-face interview using a structured questionnaire. The association of the condition with different characteristics were calculated after stratification for age, gender, occupation and monthly income. SPSS 19 was used for data analysis..Results: Of the 146 study participants, 84(57.5%) were males and 62(42.5%) were females. The overall mean age was 39±15.6 years. Of the total, 39(26.7%) had depression and anxiety. Depression and anxiety were more frequent among patients with a positive family history of mental disorders (p=0.02).Conclusion: Anxiety and depression were found to be considerably common among chronic spontaneous urticaria patients, with patients having a positive family history for mental illnesses particularly vulnerable

Neonatal Purpura Fulminans, a rare genetic disorder due to protein C deficiency: A case report.

Neonatal Purpura Fulminans is a rare and fatal disorder associated with perivascular haemorrhage and disseminated intravascular coagulation. Early clinical recognition, timely investigation and treatment is utmost important. A 6 days old baby boy was brought to emergency with blackish ulcers all over the body. Initially these were over the feet and scalp but later appeared on the abdomen. On examination, child was vitally stable, mildly icteric and had multiple erythematous large bullous blackish lesions on scalp, lower abdomen, perineum, back and soles. Neonatal reflexes and systemic examination was normal. Laboratory investigations showed normal CBC, PT/APTT and Protein S level while Protein C and Antithrombin III levels were low. Neonatal Purpura Fulminans is a life threatening condition and family screening is also mandatory for early recognition of disease in the siblings

Frequency and clinical variants of specific dermatoses in third trimester of pregnancy: a study from a tertiary care centre

OBJECTIVE: To determine the frequency of patients with dermatoses in the third trimester of pregnancy and to identify various clinical types of dermatoses in the third trimester. METHODS: The study was carried out at the Department of Dermatology and the Department of Gynaecology & Obstetrics, PNS Shifa Hospital, Karachi, from January 2 to July 1, 2008. Two hundred pregnant women in their third trimester were included in the study. The diagnosis was based on history, clinical examination and relevant investigations. Patients with physiological dermatoses and dermatoses which flare up during pregnancy were excluded. A comprehensive pro-forma was used to evaluate different dermatoses. Skin biopsy for histopathology was also done where necessary. RESULTS: The age of the study population ranged from 17 to 36 years (mean = 27.3 +/- 4.86). Five (2.5%) patients had prurigo of pregnancy, 4 (2%) had dermatoses associated with Intrahepatic Cholestasis of Pregnancy (ICP), 3 (1.5%) patients had polymorphic eruption of pregnancy, and 1 (0.5%) patient had pruritic folliculitis of pregnancy. No case of pemphigoidgestationis was observed. CONCLUSION: In the study, 6.5% patients presented with specific dermatoses. Prurigo of pregnancy was the commonest condition. Polymorphic eruption of pregnancy was more common in primigravida, while dermatoses with intrahepatic cholestasis was seen more often in multigravida

Prevalence of clinical spectrum of cutaneous adverse drug reactions in patients presenting at a tertiary care hospital in Pakistan

Introduction: Cutaneous adverse drug reactions (CADRs) are the most common adverse drug reactions reported in the literature. CADRs have resulted in disabling infirmities during hospitalization and complications following outdoor drug therapy. The pattern of CADRs and the responsible drugs usually changes with the introduction of newer drugs and evolving clinical practices. Moreover, several international studies showed variable prevalence, emphasizing the need for local data in light of different socioeconomic and demographic practices. Therefore, the purpose of this study is to evaluate the prevalence of adverse cutaneous drug reactions and identify the clinical spectrum and any potential risk factors.Methodology: The current study is a descriptive cross-sectional study conducted at Aga Khan University Hospital, Pakistan. One hundred ninety-three patients who met the study inclusion criteria were included. Data were collected from patients on a proforma after taking informed consent. Quantitative data were presented as simple descriptive statistics giving mean and standard deviation, while qualitative variables were presented as frequency and percentages. Effect modifiers were controlled through stratification to highlight the effect of these on the outcome variable. The post-stratification chi-square test was applied and the p-value of ≤0.05 was statistically significant.Results: A total of 193 patients who had cutaneous adverse drug reactions were included in the study. The mean age in this study was 47.78±8.33 years. One hundred eight (56%) were male and 85 (44%) were female. Out of 193 patients, 135 (69.9%), 50 (25.9%), 24 (12.4%), 12 (6.2%), 20 (10.4%), 11 (5.7%) and six (3.1%) had maculopapular rash, acneiform eruptions, Stevens-Johnson syndrome, erythema multiform, urticaria, fixed drug eruptions and toxic epidermal necrolysis, respectively.Conclusion: CADRs are a common clinical presentation and awareness and knowledge about their diagnosis and prevention is important. It can be assumed that in our local setup, the clinical trends and medications causing ADRs are strikingly similar to those found in other countries. Physicians commonly come across these cases and they should be well aware of the clinical spectrum of skin reactions to enable early diagnosis and management

Experimental validation of bulk-graphene as a thermoelectric generator

Quest for alternate energy sources is the core of most of the research activities these days. No matter how small or large amount of energy can be produced by utilizing the non-conventional techniques and sources, every bit of innovation can reshape the future of energy. In this work, experimental analysis of the thermoelectric (TE) properties of bulk-graphene in the temperature range of (303 to 363) K is presented. Graphene powder was pressed to form a pellet which was used to fabricate the TE device. The effects of temperature on the Seebeck coefficient, electrical and thermal conductivities, and the dimensionless figure of merit (FOM) were measured. The increasing value of the Seebeck coefficient (thermopower) with temperature is indicant of the metallic behavior. Additionally, the observed thermopower (TEP) is positive, which shows that the majority charge carriers are holes and peaked to a value of 56 μV K-1 at 363 K. The thermopower of the pellet is four times larger than the previously reported values for single layer graphene (SLG) and few layer graphene (FLG). In addition to this, low values of the thermal conductivity were observed for the pellet which is one of the requirements of a good TE material. Besides this, an upward trend is observed with increasing temperature for FOM, which attains a peak value of 0.0016 at 363 K, which is almost ten times that of the previously reported values