Saif Ur Rehman

Risk Factors and Epidemiology of Gastric Cancer in Pakistan.

Gastric cancer is the 2nd most common cause of death among all cancers and is the 4th most common cancer in the world. The number of deaths due to gastric cancer is about 800,000 annually. Gastric cancer is more common in men as compared to women and is 3rd most common cancer after colorectal and breast cancers in women. A progressive rise in the incidence rate has been observed in females over the last 5 years. The highest incidence of stomach cancer is in China, South America and Eastern Europe. The incidence of gastric cancer has 20 fold variation worldwide. Global variation is linked by two factors which play important role in developing gastric cancer. One is infection with Helicobacter pylori and the 2nd is diet. South Asia is a region with low risk, despite a high prevalence of H.pylori. Gastric carcinoma is common in southern region of India. Gastric cancer is more readily treated if diagnosed early. This study aims to provide awareness about gastric cancer as well as an updated knowledge about risk factors and epidemiology of gastric cancer in Pakistan.

Improvement in the Mechanical Properties of High Temperature Shape Memory Alloy (Ti50Ni25Pd25) by Copper Addition

High temperature shape memory alloys Ti50Ni25Pd25 and Ti50Ni20Pd25Cu5 were developed, characterized, and tensile tested in both martensite ( − 50°C) and austenite (

On enhancing the WEP security against brute-force and compromised keys

The IEEE 802.11 standard uses Wired Equivalent Privacy (WEP) for data encryption in wireless Local Area Networks. So far, different flaws have been discovered in the security of WEP. Frequently changing the encryption key can improve the security of WEP but there is no built-in provision for this in the standard. In this paper first we present and critically review different possible methods of automatic key updating and then propose a dynamic key management technique. The proposing technique works at the application layer. It is an automated encryption key updation method that can significantly improve the security of WEP without requiring any changes in the standard or at the lower layers of the OSI model.

Reliable identification of counterfeit medicine using camera equipped mobile phones

The sale of counterfeit medicine is a continuously growing global problem costing billions of dollars and effecting hundreds of thousands of precious human lives annually. Consumers of medicine have no reliable and simple way of distinguishing genuine medicine from counterfeit. In this paper we analyzed existing techniques of counterfeit medicine identification on the bases of usability, security and scalability. Different shortcomings and security weaknesses of these reviewed solutions are identified. Based on these observations, a set of requirements is determined. These requirements address different aspects of a complete solution, such as usability by end users, security of the system against various types of attacks and scalability of the solution. We then propose a framework for reliably ensuring the fidelity of purchased medicine. The proposed framework is simple to use for consumers and does not require specialized equipment, training or technology. The proposed framework will enable the consumers to verify the legitimateness of their purchased medication by using their mobile phones. Data matrix is used to make the verification code machine readable.

INAV: Minimizing delay induced by DCF control packet losses in IEEE 802.11 to optimize throughput

IEEE 802.11 uses Distributed Coordination Function (DCF) as default channel access method which is based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) where all the nodes compete for the channel access. Based on this mechanism a node cannot transmit until the medium is free. Collision can occur if two or more stations within each others transmission range transmit simultaneously. To overcome this problem several solutions have been proposed, for instance Request To Send/Clear To Send (RTS/CTS) mechanism, through which the channel is reserved for a specified time period known as Network Allocation Vector (NAV). Although this mechanism provide all the nodes to share the medium fairly but it is observed that this mechanism can lead to bandwidth underutilization, especially in networks with higher packet delivery failure rates. In this paper, we propose Intimated Network Allocation Vector (INAV) - a modified version of existing NAV mechanism - which considerably reduce bandwidth underutilization in such networks. This modification works by exploiting the backing-off feature of neighbors of the communicating nodes. The proposed technique recovers more than 93% of idle waiting time for neighbors of the nodes that fail to complete the four way handshake of RTS/CTS.

Comparison of efficacy and safety of intralesional triamcinolone and combination of triamcinolone with 5-fluorouracil in the treatment of keloids and hypertrophic scars: Randomised control trial

The treatment of keloid and hypertrophic scar is challenging with no universally accepted mode for permanent ablation. Conventional therapies yield unpredictable results, significant complications and require elaborate hardware.nnnOBJECTIVEnThe objective was to establish the safety and efficacy of intralesional 5-fluorouracil (5-FU) for the treatment of keloids and hypertrophic scars.nnnSTUDY DESIGNnRandomized controlled trial (RCT).nnnPLACE AND DURATIONnIt was conducted at the Jinnah Burn and Reconstructive Surgery Center/Allama Iqbal Medical College, Lahore, Pakistan from May 2012 to March 2013.nnnSUBJECTS AND METHODSnWe included 120 patients divided in two groups. The group A patients received intralesional triamcinolone acetonide (TAC) and the group B patients received both 5-FU and TAC. 8 injections at a week interval were given and patients were evaluated at the start of treatment and then at 4th and at 8th week during the treatment and then 4 weeks after the end of treatment. Patents were assessed for mean reduction in scar height, efficacy and complications.nnnRESULTSnTotal of 108 patients completed the study. The mean reduction in the scar height in group B (5-FU+TAC) 1.144+.4717 was markedly better than that of group A (TAC alone) 1.894+1.0751 (t=4.781, p=.000). The efficacy (defined previously as >50% reduction in initial scar height) was superior in group B 44 (77.2%) than that of group A 25 (49.0% (X2=9.260, p=.002). Recurrence was seen in 39.2% (20) of patients of the group A while in only 17.5% (10) of the cases of group B (P=0.012). Mean follow up was of 22 months.nnnCONCLUSIONn5-FU+TAC is safe, easy to administer and effective treatment for problematic scars and has the lower rate of recurrence on larger follow up.

Influence of Cu addition on transformation temperatures and thermal stability of TiNiPd high temperature shape memory alloys

In this research, four high temperature shape memory alloys, Ti50Ni25-xPd25Cux (xu2009=u20090, 5, 10 and 15) were developed and designated 0Cu, 5 Cu, 10 Cu, and 15Cu, respectively. The effect of 5%, 10%, and 15% (all in atomic percent) Cu addition was investigated through their microstructure analysis, transformation temperatures and thermal stability. After the alloying of Cu content in their desired percentage, the alloys were named as 0Cu, 5Cu, 10Cu and 15Cu alloys. The martensite onset temperature Ms of ternary 0Cu alloy increased by 12.5u2009℃, 27.5u2009℃ and 60.5u2009℃, respectively, by replacement of Ni with 5%, 10% and 15% Cu. Similarly, the austenite finish temperature Af increased by 11u2009℃, 25u2009℃, and 52u2009℃, respectively. At the same time, thermal hysteresis of the 5Cu, 10Cu, and 15Cu alloys decreased by 1.5u2009℃, 2.5u2009℃, and 8.5u2009℃, respectively, as compared to 0Cu alloy. The thermal stability of ternary 0Cu alloy was improved by replacing Ni with Cu. During thermal cycling, the net drop in Ms and Af of 0Cu alloy was 7.5u2009℃ and 14u2009℃, respectively. By replacing Ni with 5%, 10%, and 15% Cu, the net drop in Ms decreased to 5u2009℃, 3.7u2009℃, and 3u2009℃, respectively, whereas the net drop in Af decreased to 10u2009℃, 8.7u2009℃, and 5u2009℃. The overall results suggested that by the addition of 5%, 10%, and 15% Cu in place of Ni in TiNiPd alloys, the transformation temperatures and thermal stability improved. At the same time, thermal hysteresis decreased to a reasonable level which has a positive effect on the actuation behavior.