http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Shafiq, Umber (검색결과 113 건)
- 무료
- 기관 내 무료
- 유료
-
Shafiq Ul Rehman,Selvakumar Manickam 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.4
Most IPv6 security issues are still the same as IPv4; IPv6 has its own unique design characteristics that have additional impact to system and network security, as well as the potential impact on policies and procedures. Address autoconfiguration is a key feature of the IPv6 protocol stack that allow hosts to generate own addresses using a confluence of information from other hosts and information from router advertisement. Duplicate Address Detection (DAD) is a process that is part of address autoconfiguration that is used to check if the addresses generated has already been configured. Nevertheless, the design of DAD process is vulnerable to Denial of Service (DoS) attack leaving hosts unconfigured. For example, any host can reply to Neighbor Solicitations (NS) for a temporary address, causing the other host to consider it as a duplicate and eventually reject the address. Various mechanisms such as SeND and SAVI has been introduced to address such attacks, but these techniques were not very effective as there were still possibilities of DoS attacks to be carried out. As such, a new mechanism is needed to more effectively prevent DoS attacks on DAD process. In this paper, we present a detailed design and development of a novel mechanism that can address the shortfalls of existing prevention techniques.
-
Shafiq Ul Rehman,Selvakumar Manickam 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.11
In addition to addressing the scarcity of IP address space, Internet Protocol version 6 (IPv6) also addressed some of the shortcomings of Internet Protocol version 4(IPv4). These include neighbor discovery, address auto-configuration, and others. Many of this message exchange are done via the Internet Control Message Protocol (ICMP) and the use of this protocol in the IPv6 paradigm, i.e. ICMPv6 plays a bigger role compared to ICMPv4. One of the key process that is carried during neighbor discovery process is to check if the address generated already exists. This process is called the Duplicate Address Detection (DAD). Nevertheless, the design of this process has led to a severe security vulnerability allowing attackers to easily carry out Denial-of-Service (DoS) attack by causing every address generated to be a duplicate leading to new hosts unable to join the network. Various techniques and mechanisms have been introduced to address this vulnerability such as NDPMon, SeND, and SAVA. Nevertheless, these techniques are either not robust or have performance implications vis-à-vis with the DAD DoS detection and mitigation. In this paper, we put forward a novel framework that is able to detect, mitigate DoS attacks while being light-weight at the same time.
-
Shafiq, M.,Jung, Y.,Kim, S.H. IPC Science and Technology Press 2016 Biomaterials Vol.90 No.-
<P>Stem cells are a promising solution for the treatment of a variety of diseases. However, the limited survival and engraftment of transplanted cells due to a hostile ischemic environment is a bottleneck for effective utilization and commercialization. Within this environment, the majority of transplanted cells undergo apoptosis prior to participating in lineage differentiation and cellular integration. Therefore, in order to maximize the clinical utility of stem/progenitor cells, strategies must be employed to increase their adhesion, retention, and engraftment in vivo. Here, we reviewed key strategies that are being adopted to enhance the survival, retention, and engraftment of transplanted stem cells through the manipulation of both the stem cells and the surrounding environment. We describe how preconditioning of cells or cell manipulations strategies can enhance stem cell survival and engraftment after transplantation. We also discuss how biomaterials can enhance the function of stem cells for effective tissue regeneration. Biomaterials can incorporate or mimic extracellular function (ECM) function and enhance survival or differentiation of transplanted cells in vivo. Biomaterials can also promote angiogenesis, enhance engraftment and differentiation, and accelerate electromechanical integration of transplanted stem cells. Insight gained from this review may direct the development of future investigations and clinical trials. (C) 2016 Elsevier Ltd. All rights reserved.</P>
-
-
Shafiq, Muhammad,Zhang, Yue,Zhu, Dashuai,Zhao, Zongxian,Kim, Dong-Hwee,Kim, Soo Hyun,Kong, Deling Oxford University Press 2018 Regenerative biomaterials Vol.5 No.5
<P><B>Abstract</B></P><P>Cardiovascular diseases cause huge socio-economic burden worldwide. Although a mammalian myocardium has its own limited healing capability, scaffold materials capable of releasing stem cell recruiting/engrafting factors may facilitate the regeneration of the infarcted myocardium. The aim of this research was to develop cardiac patches capable of simultaneously eluting substance P (SP) and insulin-like growth factor-1C (IGF-1C) peptide. Polycaprolactone/collagen type 1-based patches with or without SP and IGF-1C peptide were fabricated by co-electrospinning, which exhibited nanofibrous morphology. SP and IGF-1C/SP patches recruited significantly higher numbers of bone marrow-mesenchymal stem cells than that of the negative control and patch-only groups <I>in vitro</I>. The developed patches were transplanted in an infarcted myocardium for up to 14 days. Mice underwent left anterior descending artery ligation and received one of the following treatments: (i) sham, (ii) saline, (iii) patch-only, (iv) IGF-1C patch, (v) SP patch and (vi) IGF-1C/SP patch. SP and IGF-1C/SP patch-treated groups exhibited better heart function and attenuated adverse cardiac remodeling than that of the saline, patch-only and individual peptide containing cardiac patches. SP patch and IGF-1C/SP patch-treated groups also showed higher numbers of CD31-positive vessels and isolectin B4-positive capillaries than that of other groups. IGF-1C/SP-treated group also showed thicker left ventricular wall in comparison to the saline and patch-only groups. Moreover, IGF-1C/SP patches recruited significantly higher numbers of CD29-positive cells and showed less numbers of Tunel-positive cells compared with the other groups. These data suggest that SP and IGF-1C peptides may act synergistically for <I>in situ</I> tissue repair. </P>
-
-
-
Services and Security Threats in SDN Based VANETs: A Survey
Shafiq, Hammad,Rehman, Rana Asif,Kim, Byung-Seo Hindawi Limited 2018 WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Vol.2018 No.-
<P>As the number of vehicles is increasing, the number of road side accidents is also increasing rapidly. The majority of these accidents is caused by the negligence of the driver. For intelligent transportation services, new protocols and architecture are continuously being developed by researchers around the globe. Thus to ensure the safety of drivers many countries are now adopting and investing a lot on vehicular ad hoc network (VANET). On the other perspective, there are many issues related to this field that must be resolved before VANET technology is practically adopted. In the case of no or low-security, several attacks can occur that may affect the efficiency and the reliability of the system. To make VANET systems more efficient software defined networking (SDN) technology is introduced in it. This technique was shortly named as SDN-based VANET. SDN-based VANET system helps us to get rid of the restriction and the challenges that are present in the simple VANET systems. It helps us to decrease the overall load on the network by managing the overall network through a single remote controller. In this survey paper, we will elaborate the concept of SDN-based VANET, its working, applications, services, security threats, and benefits over the previous techniques.</P>
-
Shafiq, Muhammad,Zhang, Qiuying,Zhi, Dengke,Wang, Kai,Kong, Deling,Kim, Dong-Hwee,Kim, Soo Hyun Lippincott WilliamsWilkins 2018 Arteriosclerosis, thrombosis, and vascular biology Vol.38 No.7
<▼1><P>Supplemental Digital Content is available in the text.</P></▼1><▼2><P><B>Objective—</B></P><P>The objective of this study was to develop small-diameter vascular grafts capable of eluting SDF (stromal cell–derived factor)-1α–derived peptide and SP (substance P) for in situ vascular regeneration.</P><P><B>Approach and Results—</B></P><P>Polycaprolactone (PCL)/collagen grafts containing SP or SDF-1α–derived peptide were fabricated by electrospinning. SP and SDF-1α peptide-loaded grafts recruited significantly higher numbers of mesenchymal stem cells than that of the control group. The in vivo potential of PCL/collagen, SDF-1, and SP grafts was assessed by implanting them in a rat abdominal aorta for up to 4 weeks. All grafts remained patent as observed using color Doppler and stereomicroscope. Host cells infiltrated into the graft wall and the neointima was formed in peptides-eluting grafts. The lumen of the SP grafts was covered by the endothelial cells with cobblestone-like morphology, which were elongated in the direction of the blood flow, as discerned using scanning electron microscopy. Moreover, SDF-1α and SP grafts led to the formation of a confluent endothelium as evaluated using immunofluorescence staining with von Willebrand factor antibody. SP and SDF-1α grafts also promoted smooth muscle cell regeneration, endogenous stem cell recruitment, and blood vessel formation, which was the most prominent in the SP grafts. Evaluation of inflammatory response showed that 3 groups did not significantly differ in terms of the numbers of proinflammatory macrophages, whereas SP grafts showed significantly higher numbers of proremodeling macrophages than that of the control and SDF-1α grafts.</P><P><B>Conclusions—</B></P><P>SDF-1α and SP grafts can be potential candidates for in situ vascular regeneration and are worthy for future investigations.</P></▼2>
-
Shafiq, Muhammad Hassan,Kamble, Nitin M.,Kim, Tae Hoon,Choi, Yoonyoung,Lee, John Hwa BioOne (American Association of Avian Pathologists 2015 Avian diseases Vol.59 No.4
<P>Live attenuated vaccines are used for effective protection against fowl typhoid (FT) in domestic poultry. In this study, a lon/cpxR/asd deletion mutant of Salmonella Gallinarum expressing the B subunit of a heat labile toxin (LTB) from Escherichia coli, a known adjuvant, was cloned in a recombinant p15A ori plasmid, JOL1355, and evaluated as a vaccine candidate in chickens. The plasmid was shown to be stable inside the attenuated Salmonella Gallinarum cell after three successive generations. Moreover, from an environmental safety point of view, apart from day 1 the JOL1355 strain was not detected in feces through day 21 postinoculation. For the efficacy of JOL1355, a total of 100 chickens were equally divided into two groups. Group A (control) chickens were intramuscularly inoculated with phosphate-buffered saline at 4 and 8 wk of age. Group B chickens were primed and boosted via the intramuscular route with 200 mL of a bacterial suspension of JOL1355 containing 1 3 10 8 colony forming units. All the chickens in Group A and B were challenged at 3 wk postbooster by oral inoculation with a wild-type Salmonella Gallinarum strain, JOL420. The JOL1355-immunized group showed significant protection and survival against the virulent challenge compared to the nonimmunized group. In addition, Group B exhibited a significantly higher humoral immune response, and the chickens remained healthy without any symptoms of anorexia, diarrhea, or depression. Group B also exhibited a significantly lower mortality rate of 4% compared to the 46% of the control group, which can be attributed to higher immunogenicity and better protection. The Group B chickens had significantly lower lesion scores for affected organs, such as the liver and spleen, compared to those of the control chickens (P < 0.01). These findings suggest that JOL1355 is a promising candidate for a safe and highly immunogenic vaccine against FT.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
