Compact circularly polarized slot-ring antenna and microstrip bandpass filter using triangular open-loop resonators

In this thesis two different research topics are undertaken, both in the area of compact RF/microwave circuits design. The first topic involves the design of a compact circularly polarized (CP) slot-ring antenna. A study of several compact CP microstrip and slotline antennas reported in the past has been carried out. In this research, a method of reducing the size of a printed slot-ring antenna is proposed. The reduction in size is achieved by introducing meandered-slot sections in the ring. Circular polarization is achieved by introducing an asymmetry, also a meandered-slot section, and feeding the antenna at an angle of 45o from the asymmetry using a microstrip feed line. The minimum axial ratio of 0.4 dB is obtained at 2.46 GHz, which is the operating frequency of the antenna. The size of the proposed antenna is reduced by about 50% compared to a conventional CP slot-ring antenna and it displays a CP bandwidth of about 2.5%. The simulated and measured results are presented, and they are in good agreement. The small size of the antenna makes it very suitable for use in modern RF/microwave wireless systems which require compact, low cost, and high performance circuits. Moreover, its CP behavior makes it more attractive for applications such as satellite communications. The second topic in the thesis involves the design of a compact microstrip bandpass filter using triangular open-loop resonators. A new compact three-pole microstrip bandpass filter using four triangular open-loop resonators is presented. A fourth resonator is placed to provide cross-coupling in the structure which gives a better skirt rejection. The measured pass-band center frequency is 2.85 GHz. The filter demonstrates about 7% bandwidth with insertion loss of less than 1 dB in the passband, a return loss of greater than 15 dB and out-of-band rejection of greater than 30 dB. The simulated and measured results are in good agreement. The proposed filter is very attractive for use in modern wireless systems which require bandpass filters having compact size, low insertion loss, high selectivity, and good out-of-band rejection

Use of complementary and alternative medicines among Malaysian cancer patients: A descriptive study

AbstractThe use of Complementary and Alternative Medicine (CAM; 補充與替代醫學 bǔ chōng yǔ tì dài yī xué) has been rapidly increasing among cancer patients. However, this pervasiveness is still largely unexplored among Malaysian cancer patients. The current study aimed to evaluate the patterns of CAM use among cancer patients from a local hospital in Malaysia. In addition, the study focused on the information-seeking behavior and CAM use disclosure to doctors. Of 393 patients, 184 (46.1%) had used CAM for their cancers. CAM usage was significantly associated with gender (p = 0.021), level of education (p = 0.001), employment status (p = 0.02), and monthly income (p < 0.001). Among frequently used CAM were nutritional supplements (n = 77, 41.8%), natural products (n = 74, 40.2%), and multivitamin (n = 62, 33.6%). Friends and family members were the most common source of CAM information (n = 139, 75.5%). Seventy-nine (43%) reported to disclose their CAM use to the health care providers. The most common (n = 63, 34.2%) reason of nondisclosure was “it is not important to discuss it with oncologist.” This study confirmed that CAM use is common among Malaysian cancer patients, thus highlighting a greater need for patient education regarding CAM therapies and their potential interactions with conventional therapies. Although some types of CAM therapies may help patients to cope with emotional distress and improve quality of life, CAM, with no proven efficacy, may pose dangers to patients' health due to interactions with conventional therapies. Doctors and other health care providers including nurses and pharmacists should engage cancer patients in an open nonjudgmental dialog to ascertain CAM use disclosure to their health care providers

Does treatment adherence correlates with health related quality of life? findings from a cross sectional study

Abstract Background Although medication adherence and health-related quality of life (HRQoL) are two different outcome measures, it is believed that adherence to medication leads to an improvement in overall HRQoL. The study aimed to evaluate the association between medication adherence and HRQoL. Methods A questionnaire-based cross-sectional study design was undertaken with hypertension patients attending public hospitals in Quetta city, Pakistan. HRQoL was measured by Euroqol EQ-5D. Medication adherence was assessed by the Drug Attitude Inventory. Descriptive statistics was used to tabulate demographic and disease-related information. Spearmans correlation was used to assess the association between the study variables. All analysis was performed using SPSS 17.0. Results Among 385 study patients, the mean age (SD) was 39.02 (6.59), with 68.8% of males dominating the entire cohort. The mean (SD) duration of hypertension was 3.010.939years. Forty percent (n=154) had a bachelors degree level of education with 34.8% (n=134) working in the private sector. A negative and weak correlation (0.77) between medication adherence and EQ-5D was reported. In addition, a negative weak correlation (0.120) was observed among medication adherence and EQ-VAS. Conclusions Correlations among the study variables were negligible and negative. Hence, there is no apparent relationship between the variables.</p

A qualitative exploration of Malaysian cancer patients’ perceptions of cancer screening

<p>Abstract</p> <p>Background</p> <p>Despite the existence of different screening methods, the response to cancer screening is poor among Malaysians. The current study aims to examine cancer patients’ perceptions of cancer screening and early diagnosis.</p> <p>Methods</p> <p>A qualitative methodology was used to collect in-depth information from cancer patients. After obtaining institutional ethical approval, patients with different types and stages of cancer from the three major ethnic groups (Malay, Chinese and Indian) were approached. Twenty semi-structured interviews were conducted. All interviews were audiotaped, transcribed verbatim, and translated into English for thematic content analysis.</p> <p>Results</p> <p>Thematic content analysis yielded four major themes: awareness of cancer screening, perceived benefits of cancer screening, perceived barriers to cancer screening, and cues to action. The majority of respondents had never heard of cancer screening before their diagnosis. Some participants reported hearing about mammogram and Pap smear tests but did not undergo screening due to a lack of belief in personal susceptibility. Those who had negative results from screening prior to diagnosis perceived such tests as untrustworthy. Lack of knowledge and financial constraints were reported as barriers to cancer screening. Finally, numerous suggestions were given to improve screening behaviour among healthy individuals, including the role of mass media in disseminating the message ‘<it>prevention is better than cure</it>’.</p> <p>Conclusions</p> <p>Patients’ narratives revealed some significant issues that were in line with the Health Belief Model which could explain negative health behaviour. The description of the personal experiences of people with cancer could provide many cues to action for those who have never encountered this potentially deadly disease, if incorporated into health promotion activities.</p