Effect of surfactant concentration on the evaporation-driven deposition of carbon nanotubes: from coffee-ring effect to strain sensing

Carbon nanotubes (CNTs) as electrically conductive materials are of great importance in the fabrication of flexible electronic devices and wearable sensors. In this regard, the evaporation-driven self-assembly of CNTs has attracted increasing attention. CNT-based applications are mostly concerned with the alignment of CNTs and the density of CNT films. In the present work, we focus on the latter by trying to achieve an optimal evaporation-driven deposition with the densest CNT ring. Although surfactants are used for effective dispersion and colloidal stabilization of CNTs in the aqueous phase, their excessive usage induces Marangoni eddies in the evaporating sessile droplets, leading to poor ring depositions. Thus, there is an optimum surfactant concentration that contributes to CNTs deagglomeration and results in the densest ring-like deposition with relatively high thickness. We report that this optimum concentration for sodium dodecyl sulfate (SDS) as a surfactant can be approximately considered as much as the concentration of multi-walled carbon nanotubes (MWCNTs) as the colloidal nanoparticles. Optimal depositions show the lowest electrical resistances for each CNT concentration, making them suitable for electronic applications. We also propose the multiple depositions method in which a new droplet is printed after the complete evaporation of the previous droplet. This method can lead to denser rings with a higher conductivity using lower concentrations of CNTs. Lastly, we fabricate strain sensors based on the optimal evaporation-driven deposition of CNTs which show higher gauge factors than the commercial strain gauges, corroborating the applicability of our method.

Our discovery reveals the existence of an optimum SDS/CNT concentration ratio to achieve the highest conductivity of ring deposition for strain sensing.     

Clinical evaluation of desferrioxamine (DFO) for removal of thallium ions in rat

An investigation was conducted to evaluate the ability of DFO following the administration of thallium salt in male Wistar rats. Thallium was introduced to several groups of weanling male Wistar rats via different means, through drink, food and intraperitoneal injection. A control group was fed on a diet containing a normal level of iron. After a period of 30 days, all the rats administered thallium were severely anemic and showed toxicity symptoms through loss of hair, an increase in thallium and a decrease in iron levels in the blood. Chelation therapy was carried out to remove the toxic element from the body. The ability of desferrioxamine (DFO) in removing thallium was investigated by injection of this chelator for one week to the remaining rats of similar groups. The results showed that the thallium level present in the blood was significantly reduced and, at the same time, the iron concentration returned to the normal level. It was concluded that DFO chelator is able to remove thallium from the body and could be used for the treatment of complications and eradication of symptoms of thallium intoxication.     

First reported case of delayed‐type hypersensitivity reaction to non‐hyaluronic acid Polycaprolactone dermal filler following COVID‐19 vaccination: A case report and a review of the literature

Cases of filler reactions after COVID‐19 vaccination have been reported. Here, we present the first case of delayed‐type reaction (DTR) to non‐hyaluronic acid Polycaprolactone dermal filler after the second dose of Sinopharm COVID‐19 vaccine which was improved with administration of topical and intralesional steroids.     

Prevalence and incidence of diabetes in HIV-infected minority patients on protease inhibitors

In HIV-infected patients, the use of protease inhibitors (PIs) is associated with a constellation of abdominal obesity; buffalo hump; decreased facial and subcutaneous fat; hyperlipidemia and type-2 diabetes mellitus, a so-called HAART-associated dysmetabolic syndrome. The incidence and prevalence of one of its components, the type-2 diabetes mellitus, among minority population is unknown. In August and September 1999, we reviewed 101 charts of HIV-infected patients who visited an inner-city HIV outpatient clinic. The age, gender, ethnicity, BMI, fasting plasma glucose, random serum glucose, triglycerides, CD4 counts, and the type and duration of antiretroviral drugs were recorded. Three years later (2002), the same patient charts were reviewed for evidence of new-onset diabetes. Ten percent of the subjects were identified as diabetic at baseline. The prevalence of diabetes was 12% among those who were taking PIs, compared to 0% among those who were not taking PIs. The incidence of newly diagnosed diabetes during this three-year period was 7.2%. Diabetes occurred only in the group taking PIs. Diabetic subjects were older than their nondiabetic counterparts. All were African Americans. Our study suggests that PIs increase the likelihood of diabetes developing with increasing age in African Americans infected with HIV.     

ImmunoDip: an improved screening method for microalbuminuria

BACKGROUND: It is important to test for microalbuminuria in patients with diabetes, hypertension and possible insulin resistance syndrome. Current screening methods are suboptimal. This study evaluates a new office screening test for microalbuminuria that utilizes a monoclonal antibody against human serum albumin (ImmunoDip). METHODS: 182 urine samples were collected from patients attending diabetes, nephrology or hypertension clinics. The ImmunoDip screening test was carried out in the 182 samples after which albumin and creatinine concentrations were measured quantitatively in a reference laboratory. RESULTS: Screening the 182 patient samples with ImmunoDip and designating an albumin:creatinine ratio of > or =30 microg/mg as positive yielded a sensitivity of 96%, a specificity of 80%, a positive predictive value (PPV) of 66% and a negative predictive value (NPV) of 98%. The reduced specificity and PPV were not due to an intrinsic inaccuracy with ImmunoDip screening of these samples, but rather was shown to be due to the discordance between the accepted upper limits of normal for the albumin:creatinine ratio (30 microg/mg) and the albumin concentration (20 mg/l), the latter corresponding to a ratio of 20 microg/mg. In 35 samples with albumin concentrations of 20-50 mg/l, ImmunoDip screening yielded only one false negative (FN) result. CONCLUSIONS: ImmunoDip is an excellent screening tool for microalbuminuria.     

Correlates of the Intention to Remain Sexually Inactive Among Male Adolescents in an Islamic Country: Case of the Republic of Iran

BACKGROUND:  There are very few studies that have examined sexual intentions and behaviors of adolescents in Islamic countries. This study employs the Health Belief Model to assess the correlates of the intention to remain sexually inactive among male adolescents in the Republic of Iran.
METHODS:  This cross-sectional study was performed with a sample of 314 adolescents recruited from 3 high schools from Tehran, Iran.
RESULTS:  Fifty-seven percent of this sample planned to remain abstinent until marriage. Another 23% rejected the notion of remaining abstinent and 20% were uncertain. Multinomial logistic regression revealed that students whose mothers were employed and who received a higher daily allowance were more likely to report that they would not remain abstinent. No significant independent relationship between human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome-related knowledge and an intention to remain abstinent was detected. However, consistent with previous studies conducted in Asia, Africa, and in Western countries, we documented that (1) perceived subjective norms, (2) self-efficacy, (3) and perceived susceptibility to contracting the HIV virus all are associated with the intention to remain sexually inactive among adolescents.
CONCLUSIONS:  It seems abstinence until marriage is more likely to be practiced in traditional families. However, Iranian society is changing rapidly and traditional family structures, values, and norms may not sufficiently protect adolescents from HIV infection. The data from this study support previous studies conducted in Western countries, which found that intervention programs that focus on knowledge alone are ineffective in their ability to alter adolescents' intentions to postpone sexual activity.     

Prospective analysis of serum carotenoids,vitamin A,and tocopherols in adults with short bowel syndrome undergoing intestinal rehabilitation

ObjectiveCarotenoids, vitamin A, and tocopherols serve important roles in many key body functions. However, availability of these compounds may be decreased in patients with short bowel syndrome (SBS) due to decreased oral intake of fruits and vegetables and/or decreased intestinal absorption. Little information is available on serum concentrations of carotenoids, vitamin A, and tocopherols during chronic parenteral nutrition (PN) or during PN weaning. The aim of this study was to prospectively examine serum concentrations of a wide variety of carotenoids, vitamin A, and tocopherols in patients with SBS undergoing an intensive 12-wk intestinal rehabilitation program.MethodsTwenty-one PN-dependent adult patients with SBS were enrolled in a 12-wk intestinal rehabilitation program, which included individualized dietary modification, multivitamin supplementation, and randomization to receive subcutaneous placebo (n = 9) or human growth hormone (0.1 mg · kg^?1 · d^?1; n = 12). PN weaning was initiated after week 4 and advanced as tolerated. Serum concentrations of carotenoids, vitamin A, and tocopherols were determined at baseline and at weeks 4 and 12.ResultsA significant percentage of subjects exhibited low serum concentrations for carotenoids and α-tocopherol at study entry, and a few subjects had low concentrations of retinol (5%). Carotenoid and vitamin A valves did not improve over time, while α-tocopherol levels rose. Serum α-tocopherol concentration was negatively associated with PN lipid dose (r = ?0.34, P < 0.008).ConclusionPatients with SBS are depleted in diet-derived carotenoids despite oral and intravenous multivitamin supplementation and dietary adjustment during intestinal rehabilitation and PN weaning. Reduction of PN lipid infusion may improve serum α-tocopherol concentrations.     

Access to vision care in an urban low-income multiethnic population

OBJECTIVE: This study applied a well-known, recently revised theoretical model of healthcare access and utilization, the Behavioral Model for Vulnerable Populations, to examine the relationship between access to care and utilization of eye care services among a multiethnic, predominately minority sample of residents from low-income public housing. DESIGN: Population-based, cross-sectional survey of community sample. SETTING: Urban Public Housing Communities in Los Angeles County, California. PARTICIPANTS: A geographically defined stratified random sample of 152 residents (86% Latino or African American) 40 years of age and older from three urban public housing communities. RESULTS: Only 62% of our sample of persons 40 years and older had received an eye examination within the past 2 years. Sixty-one percent of participants reported having vision care coverage. Yet, one out of four respondents claimed that no health care provider had ever told them that they needed an eye-examination. Applying multiple logistic regression and controlling for a number of predisposing, enabling, and need-for-care characteristics, the variables 1) receiving advice from health care providers for eye examination (OR = 3.9, p < 0.01), 2) possessing coverage for eye-care (OR = 3.2, p < 0.01), and 3) having regular and continuity of medical care (OR = 2.4, p < 0.01) remained significant predictors of eye-examination within the past 2 years. CONCLUSION: This study documents significantly diminished utilization of eye care services relative to recommended guidelines for a low-income, predominately minority sample of residents from public housing communities. We documented no association between presence of diabetes or hypertension and recency of eye examination. Affordability, continuity, and regular sources of care, as well as receiving physician advice, remain the core factors significantly associated with receiving vision care. These results underscore the need for continued efforts to ensure that the medically underserved minority have access to vision care services. These findings also point toward the urgent need for educational and motivational interventions that encourage health care providers serving underserved communities to promote eye examination, particularly among diabetic patients, hypertensive patients, and other individuals at risk for eye-related disease and complications.