Nursing students' perspectives on learning math for medication calculations in a Canadian nursing program in Qatar.

This study describes nursing students' perspectives on learning math for medication calculations in a Canadian baccalaureate nursing program in Qatar. There is a dearth of guidance within the nursing literature to support teachers to develop pedagogical methods to help improve students' math competence. Moreover, the challenge of teaching math skills to student nurses in Qatar is particularly difficult because there is little standardization of curricula in secondary education. Data collected from focus groups was analyzed using interpretive description. Focus groups included, Group 1 those students who were beginning to learn math for medication calculations and had not completed the required math module and Group 2, students who had not yet completed the math module. Themes emerging from the data included from first year students, 1. Fear of math resulting in resistance to learning math for medication administration. 2. Student success is dependent on good instructors. 3. Student resentment towards perceived 'complicated' math in the nursing program. Themes from second year students included 1. Lack of nursing student's confidence with medication calculation within the clinical settings 2. Lack of self-directedness to uptake math knowledge 3. Incongruence amongst clinical instructors with applied math practice whilst in the clinical setting.

Numerical study of the effect of vascular bed on heat transfer during high intensity focused ultrasound (HIFU) ablation of the liver tumor.

In this study, the influence of vascular bed comprising terminal arterial branches on heat transfer in a liver tumor exposed to high intensity focused ultrasound (HIFU) is studied numerically. Also, the effect of vascular density on temperature distribution is investigated. A coupled set of acoustics, thermal, and fluid models is used to calculate the temperature distribution in the liver. The numerical model is established based on the Westervelt and bioheat equations along with the Navier-Stokes equations. Moreover, the acoustic streaming effect is included with Newtonian and non-Newtonian flow assumptions. It is found that in a vascular bed comprising terminal arterial branches, the effect of acoustic streaming is negligible because of the small diameter of these vessels, and the non-Newtonian behavior of blood flow reduces the peak streaming velocity. It is also shown that the vascular density (amount of tissue vascular content) has a considerable cooling effect on peak temperature and hence lesion volume in the liver and, by increasing the vascular density, the treatment duration is prolonged. Results show that when the tumor is embedded in the vascular bed, the cancer cells near the vessels walls remain viable. Some approaches are proposed and compared to improve the efficacy of HIFU in a tumor located in the vascular bed. These approaches include increasing the source pressure or transducer gain. It is concluded that for the assumed configuration of the vascular bed, adjusting the transducer gain is preferred to increase the lesion size and to prevent the problems related to skin burns simultaneously.

Targeted energy transfer and modal energy redistribution in automotive drivetrains.

The new generations of compact high output power-to-weight ratio internal combustion engines generate broadband torsional oscillations, transmitted to lightly damped drivetrain systems. A novel approach to mitigate these untoward vibrations can be the use of nonlinear absorbers. These act as Nonlinear Energy Sinks (NESs). The NES is coupled to the primary (drivetrain) structure, inducing passive irreversible targeted energy transfer (TET) from the drivetrain system to the NES. During this process, the vibration energy is directed from the lower-frequency modes of the structure to the higher ones. Thereafter, vibrations can be either dissipated through structural damping or consumed by the NES. This paper uses a lumped parameter model of an automotive driveline to simulate the effect of TET and the assumed modal energy redistribution. Significant redistribution of vibratory energy is observed through TET. Furthermore, the integrated optimization process highlights the most effective configuration and parametric evaluation for use of NES.

Time to seroconversion of HBsAg to anti-HBs in individuals who lost HBsAg during follow-up.

To determine the time to appearance of antibody against hepatitis B surface antigen (anti-HBs) after clearance of hepatitis B surface antigen (HBsAg) in chronically infected individuals, we followed up 3963 cases with positive antibody against hepatitis B e antigen (anti-HBe) from 1991 to 2014. Of these, 101 (67 males, 34 females) lost HBsAg. These serocleared cases were checked every 6-month interval regarding HBsAg, anti-HBs, liver function tests, and liver sonography. Hepatitis B virus DNA was assessed at the time of seroclearance or the appearance of anti-HBs. The mean age of these patients at entry to this study was 34·4 ± 13 years. The mean follow-up duration until seroclearance of HBsAg was 6·6 ± 4·3 years. After the mean follow-up of 43·7 ± 45 months, anti-HBs appeared in 64 (63·4%) cases. The cumulative probabilities of anti-HBs appearance for 2, 5 and 10 years were 24·3%, 58% and 78·2%, respectively. The appearance of anti-HBs was associated with age ⩾35 years and seroclearance of HBsAg (hazard ratio 1·96, 95% confidence interval 1·32-3·38, P = 0·016) but not with sex. The results show that anti-HBs may develop in 78·2% of cases within 10 years of HBsAg clearance. Age ⩾35 years at HBsAg loss was associated with earlier development of anti-HBs.

Synthesis and antioxidant evaluation of some novel ortho-hydroxypyridine-4-one iron chelators.

A series of ortho-hydroxypyridine-4-ones were prepared in high yields and evaluated for antioxidant and iron chelating activities. N(1)-H hydroxypyridinones Va, Vb, and Ve were the best radical scavengers in DPPH free radical scavenging assay. Compound Vb was proved to be the most potent compound in hydrogen peroxide scavenging assay. All of the synthesized compounds had very close chelating ability, compounds containing N(1)-CH3 hydroxypyridinone ring were stronger chelating agents.

Compliance of Iranian dentists with safety standards of oral radiology.

OBJECTIVES: Dentists use radiographs in their daily practice. Their knowledge and behaviour towards radiographic examination can affect patients' exposure to radiation. The aim of this study was to survey the knowledge and behaviour of Iranian dentists regarding oral radiology safety standards. METHODS: 1000 questionnaires were given to the participants of the 48th Annual Congress of the Iranian Dental Association, of which 700 were returned. The participants were asked about demographic data, primary knowledge of radiation protection, selection criteria, radiographic equipment and technique, methods of patient and personnel protection and management of radiographic waste. Descriptive analysis of data was performed. RESULTS: 44% of respondents said the initial radiograph they took was of the periapical view of a limited area. 12% preferred the periapical paralleling technique. F-speed film was used by 9% and E-speed film by 62%. Only 2% had digital receptors. Proper exposure time was selected by 26.5%. The use of long and rectangular collimators was 15% and 6%, respectively. 34% occasionally covered their patients with both thyroid shields and lead aprons. 36% used the position and distance rule correctly for their own protection. Proper disposal of the used processing solutions and the lead foils were done by only 1% and 3%, respectively. CONCLUSIONS: It can be concluded that the majority of dentists in the study group did not select the proper method, material and equipment in order to minimize the exposure of their patient to unnecessary radiation in dental radiography.

Outcomes of acute postoperative inflammation after cataract surgery.

PURPOSE: To determine characteristics and final visual and surgical outcomes of patients who experienced early onset postoperative inflammation after cataract surgery and their early and late complications. METHODS: This is a prospective case series of 126 patients out of 1500 cases who underwent cataract surgery and experienced early onset postoperative inflammation during the first 2 weeks after cataract surgery. All the patients received complete ocular examinations at onset of signs and symptoms of inflammation. A total of 110 patients with follow-up examinations between 3 and 30 months after recovery of early onset postoperative inflammation (mean follow-up 11.6 months) were enrolled in the next part of the study to evaluate the final visual and surgical outcomes. Background systemic and ocular diseases, type of surgery, type of intraocular lenses and viscoelastic agent, early and late complications, and final best-corrected visual acuity were studied. RESULTS: Among 1500 patients, 126 cases (8.4%) had early onset postoperative inflammation, 64 cases (50.7%) were male, and 62 cases (49.3%) were female. Early complications were posterior synechia in 9 cases (7.1%), pupillary block in 2 cases (1.5%), and acute rise of intraocular pressure in 6 cases (4.7%). Late complications consisted of posterior capsular opacity in 38 cases (34.5%) and cystoid macular edema in 4 cases (3.2%). Peak of signs and symptoms of inflammation was during 2 weeks after surgery and all patients responded well to topical steroids. Final best-corrected visual acuity (BCVA) was 20/30 and better in 76 cases (69%), between 20/40 and 20/80 in 24 cases (22%), and less than 20/80 in 10 cases (9%). All cases with BCVA less than 20/80 had ocular diseases like choroidal neovascularization scar or age-related macular degeneration, advanced glaucoma, or corneal opacity. CONCLUSIONS: Early onset postoperative inflammation causes pain, decreased vision, and patient anxiety in the acute phase but neither decreases final visual acuity nor has any significant or permanent ocular sequels.

Limbal stem cell deficiency in the context of autoimmune polyendocrinopathy.

PURPOSE: To report two sisters with bilateral progressive visual loss and photophobia secondary to stem cell deficiency due to multiple endocrine deficiency. METHODS: Case reports and review of medical literature. RESULTS: The younger sister had severe photophobia and decreased visual acuity since May 2000. Despite multiple outpatient visits no definite cause was found and conservative treatments failed. On slit lamp examination severe meibomian gland dysfunction, loss of eyelashes, decreased tear meniscus, diffuse corneal vascularization, and delayed punctate fluorescein staining of corneal epithelium were detected. She also had episodes of hypotension, oral candidiasis, and seizures. Her systemic workup revealed multiple endocrine deficiency (Addison's disease and hypoparathyroidism). Hormone replacement therapy with fludrocortisone and oral calcium accompanied by punctual occlusion led to significant clinical recovery . The older sister showed a similar pattern but interestingly the onset was later and the signs and symptoms were milder. CONCLUSIONS: In the pediatric age group with diffuse corneal vascularization and no definite cause, systemic workup should be done to rule out multiple endocrine deficiencies. The therapy consists of hormone replacement therapy and management of dry eye.

Causes of severe visual impairment and blindness in schools for visually handicapped children in Iran.

AIMS: This survey was conducted on children in schools for the blind in Tehran (from 2002 to 2003) to determine the causes of severe visual impairment and blindness and to identify preventable and treatable conditions. METHODS: The study was performed on 362 students at different grades in three schools for the blind. Patient sex, age, family history of blindness or low vision, visual acuity, causes of blindness, and treatable and preventable conditions were studied. RESULTS: Of the 362 cases, 210 (58%) were boys and 152 (42%) were girls. Mean age was 13.5 (SD 4) years. Severe visual loss was seen in 80.9%. Retinal diseases were the most common cause for low vision (51%); cataract, optic nerve atrophy, corneal and anterior segment diseases, glaucoma, anophthalmia, and globe malformations were other major causes of blindness. Treatable aetiologies and positive family history of blindness were seen in 25.7% and 36% of the patients, respectively. The incidence of preventable diseases, excluding familial disorders, was low. CONCLUSION: In addition to the prevention and treatment of some conditions, premarital genetic counselling and family planning control in families with inherited diseases could decrease the number of blind children in the future in Iran.

Soy-polysaccharide-supplemented soy formula enhances mucosal disaccharidase levels following massive small intestinal resection in rats.

BACKGROUND: Addition of soy polysaccharide to infant formulas has previously been shown to reduce the duration of diarrhea in infants with acute gastroenteritis. Fiber is metabolized to short-chain fatty acids that have been shown to be beneficial in inducing adaptation in the small bowel. We therefore hypothesize that a soy-polysaccharide-supplemented infant formula may be potentially advantageous in the treatment of patients with short bowel syndrome and could have a trophic effect on the remaining small intestine. METHODS: Male Spraque-Dawley rats weighing 250 g were divided into two groups. One group received Isomil, a standard infant soy formula. The second group received Isomil supplemented with fiber, Isomil DF. Half the animals in each dietary group were subjected to 80% jejunoileal resection and the reminder were sham operated. Animals were pair-fed one of two diets for 14 days. At the conclusion of the 14-day period, mucosal weight and sucrase and lactase levels in the remaining duodenum and ileum were determined. RESULTS: Resected animals fed fiber-supplemented formulas had significantly higher sucrase and lactase levels in the proximal bowel. Comparable results were not observed in the sham-operated animals. CONCLUSIONS: The addition of soy polysaccharide to infant formulas fed to children with short bowel syndrome might potentially improve small intestinal functional adaptation as well as positively affecting stool consistency.

In vitro digestion of dystrophin by calcium-dependent proteases, calpains I and II.

Dystrophin is a cytoskeletal protein which is thought to play an important role in membrane physiology since its absence (due to gene deficiency) leads to the symptoms of Duchenne muscular dystrophy (DMD). Some disruption in the regulation of intracellular free Ca2+ levels could lead to DMD-like symptoms. In this study, calpains, which are very active calcium-dependent proteases, were examined for their capacity to hydrolyse dystrophin in vitro. The results show that calpains are able to split dystrophin and produce breakdown products of different sizes (the degree of cleavage being dependent on the incubation time with proteases). The time-course of protease degradation was examined by Western immunoblot using three polyclonal sera which were characterized as being specific to the central (residues 1173-1728) and two distal parts of the molecule ie specific to the N-terminal (residues 43-760) or the C-terminal (residues 3357-3660) extremities of the dystrophin molecule. The cleavage patterns of dystrophin showed an accumulation of some major protease-resistant fragments of high relative molecular mass (250-370 kDa). These observations demonstrate that calpains digest dystrophin very rapidly when the calcium concentration is compatible with their activation. For instance, it is clear that calpains first give rise to large dystrophin products in which the C-terminal region is lacking. These observations suggest that dystrophin antibodies specific to the central domain of the molecule should be used to detect dystrophin for diagnostic purposes and before any conclusion as to the presence or absence of dystrophin can be deduced from results obtained using immunoanalyses of muscle biopsies.