4,437 research outputs found
Correlations in nuclear energy recurrence relations
The excitation energies of states belonging to the ground state bands of
heavy even-even nuclei are analysed using recurrence relations. Excellent
agreement with experimental data at the 10 keV level is obtained by taking into
account strong correlations which emerge in the analysis. This implies that the
excitation energies can be written as a polynomial of maximum degree four in
the angular momentum.Comment: 4 pages, 1 figure, 1 table, 9 reference
Intragastric balloons for obesity: critical review of device design, efficacy, tolerability, and unmet clinical needs
Introduction
Sustaining a healthy weight is a challenge and obesity, with associated risk of co-morbidities, is a major public health concern. Bariatric surgery has shown a great promise for many where pharmacological and lifestyle interventions failed to work. However, challenges and limitations associated with bariatric surgery has pushed the demand for less invasive, reversible (anatomically) interventions, such as intragastric balloons (IGBs).
Areas covered
This review critically appraises IGBs used in the past, present, and those in clinical trials, discussing the device designs, limitations, placement and removal techniques, patient eligibility, efficacy, and safety issues.
Expert opinion
Several intragastric balloons were developed over the years that brought excitement to patients and healthcare professionals alike. Albeit good efficacy, there had been several safety issues reported with IGBs such as spontaneous deflation, intestinal occlusion, gut perforation, and mucosal ulcerations. This led to evolution of IGBs design; device material, filling mechanism, fluid type, inflation volume, and further innovations to ease ingestion and removal of device. There are some IGB devices under development aimed to swallow like a conventional pill and excrete naturally through defecation, however, how successful they will be in clinical practice in terms of their efficacy and tolerability remains to be seen in the future
Current and Shot Noise Measurements in a Carbon Nanotube-Based Spin Diode
Low-temperature measurements of asymmetric carbon nanotube (CNT) quantum dots
are reported. The CNTs are end-contacted with one ferromagnetic and one
normal-metal electrode. The measurements show a spin-dependent rectification of
the current caused by the asymmetry of the device. This rectification occurs
for gate voltages for which the normal-metal lead is resonant with a level of
the quantum dot. At the gate voltages at which the current is at the maximum
current, a significant decrease in the current shot noise is observed
Electromagnetic Transition Strengths in Heavy Nuclei
We calculate reduced B(E2) and B(M1) electromagnetic transition strengths
within and between K-bands in support of a recently proposed model for the
structure of heavy nuclei. Previously, only spectra and a rough indication of
the largest B(E2) strengths were reported. The present more detailed
calculations should aid the experimental identification of the predicted ,
and bands and, in particular, act to confirm or refute the
suggestion that the model and bands correspond to the well known
and widespread beta and gamma bands. Furthermore they pinpoint transitions
which can indicate the presence of a so far elusive band by feeding
relatively strongly into or out of it. Some of these transitions may already
have been measured in Th, Th and U.Comment: 10 pages, 1 Figure, submitted to Physical Review
Probing the exchange field of a quantum-dot spin valve by a superconducting lead
Electrons in a quantum-dot spin valve, consisting of a single-level quantum
dot coupled to two ferromagnetic leads with magnetizations pointing in
arbitrary directions, experience an exchange field that is induced on the dot
by the interplay of Coulomb interaction and quantum fluctuations. We show that
a third, superconducting lead with large superconducting gap attached to the
dot probes this exchange field very sensitively. In particular, we find
striking signatures of the exchange field in the symmetric component of the
supercurrent with respect to the bias voltage applied between the ferromagnets
already for small values of the ferromagnets' spin polarization.Comment: published version, 10 pages, 7 figure
What is the effect of riskshaw noise on its driver?
Objective: Occupational hearing loss is common in the industrialized world. Road noise is a major contributor to perceived environmental noise. The objective of this study was to assess hearing loss in rickshaw drivers due to rickshaw noise.Methods: Hearing loss in rickshaw drivers and taxi drivers of Karachi who were 50 years of age or younger was estimated, with a Smith Hearing Screening (SHS) questionnaire that was modified, translated into the national language, Urdu and field tested prior to administration.Results: Interviews for 91 rickshaw drivers and 94 taxi drivers were completed. All subjects were male; mean ages were 34 and 33 years for rickshaw and taxi drivers respectively. None of the rickshaws were fitted with silencers. Rickshaw drivers were about thrice as likely to be screened as hearing impaired by the SHS questionnaire (RR 2.9, 95% confidence interval 1.6, 5.0), twice as likely to report tinnitus (RR 2.2, 95% confidence interval, 1.1, 3.3) and two and a half times as likely to have difficulty in following telephonic conversations (RR 2.4, 95% confidence interval 1.2, 4.8).CONCLUSION: There is loss of hearing and tinnitus among rickshaw drivers that could be attributed to their trade. Use of silencers by rickshaw drivers could result in less hearing loss among rickshaw drivers and less noise in the environment for the other 11 million residents in the city
Effect of prepregnancy body mass index and gestational weight gain on birth weight
Objective: Nutritional status of women has been considered an important prognostic indicator of birth outcome. The study aims to show the effect of various prepregnancy Body Mass Index (BMI) categories and corresponding gestational weight gain on newborn birth weight.Methods: Two hundred women were included in the study. These women had regular antenatal visits and later delivered at The Aga Khan University Hospital (AKUH) between the period January 1, 1996 to December 31, 1997.Results: For women with prepregnancy BMI \u3c 19., mean birth weight of newborns was lower for those gaining \u3c 12.5 kg than those gaining \u3e 12.5 kg (P \u3c 0.001). Women who started their pregnancy with BMI 19.8-26 and gained weight above expected range gave birth to high birth weight babies (P = 0.009). Gestational weight gain did not have a significant association with birth weight for women having prepregnancy BMI \u3e 26.Conclusion: Efforts should be made to attain adequate prepregnancy weight to reduce the likelihood of low birth weight babies. Hence, special attention should be paid to women with low prepregnancy BMI
Smoking among males in a low socioeconomic area of Karachi
Approximately half of the families in Pakistan reported having at least one smoker in 1992. Smokers were less educated, poorer and more likely to come from a rural background than non-smokers. The proportion of family earnings in poor families with marginal incomes, may be substantial. We conducted this survey to determine the prevalence of cigarette smoking in males over 15 years of age in Azam Basti, an urban squatter settlement of Karachi where 31% of the children less than 5 years old were malnourished. A pretested, structured questionnaire was administered to males aged fifteen years and above, from randomly selected homes in Azam Basti. In our sample of 102 persons the respondents were 38 years old on average, and earned about Rs. 4,500 (US 140) (OR = 2.4, 95% confidence interval 0.8, 7.3). Smoking is common in urban squatter settlements in Pakistan. Parental smoking and its relationship with malnutrition in children under five is not well documented or publicized, even though there is evidence that it has a contribution. We propose that primary health care programs consider smoking prevention and cessation as community based interventions
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