Comparative features and outcomes of malaria at a tertiary care hospital in Karachi, Pakistan.

OBJECTIVES: A comparison of clinical and laboratory features, diagnostic methods, drug treatment, and outcomes for patients hospitalized with malaria by Plasmodium species. METHODS: Records of 521 patients hospitalized during the four and half-year study period were analyzed. RESULTS: Infections were caused by Plasmodium vivax (51.8%), Plasmodium falciparum (46.5%), P. vivax plus P. falciparum (1.3%), and Plasmodium malariae (0.4%). Vomiting (odds ratio (OR)=1.86, p=0.001) and abdominal pain (OR=1.60, p=0.024) occurred more frequently in patients infected with P. falciparum compared to P. vivax; this was also the case for hepatomegaly, splenomegaly and jaundice. Low hemoglobin levels were common but were significantly lower with P. falciparum, and creatinine levels were significantly higher with P. falciparum. Treatment regimens consisted of single drug therapy (61.5%), appropriate combination therapy (15.8%), and inappropriate combination therapy (22.7%). Antimalarials given alone included chloroquine (38.7%), quinine (19%) and doxycycline (1.5%). The overall mortality was 1.7% (n=9) and nearly 56% of patients developed disease complications, most commonly thrombocytopenia (36.4%), anemia (23.4%), and thrombocytopenia plus anemia (32.7%). CONCLUSIONS: Despite resistance, chloroquine was prescribed in patients with malaria requiring hospitalization. We found a high proportion of single antimalarial drug use as well as inappropriate combination therapy (22.7%), and inadequate use of primaquine terminal prophylaxis. Physicians need to be acquainted with malaria treatment guidelines in an endemic zone.     

Modulation masking release using the Brazilian-Portuguese HINT: Psychometric functions and the effect of speech time compression

Objective: The Brazilian-Portuguese hearing in noise test (HINT) was used to investigate the benefit to speech recognition of listening in a fluctuating background. The goal was to determine whether modulation masking release varied as a function of the speech-to-masker ratio at threshold. Speech-to-masker ratio at threshold was manipulated using the novel approach of adjusting the time-compression of the speech. Design: Experiment 1 measured performance-intensity functions in both a steady speech-shaped noise masker and a 10-Hz square-wave modulated masker. Experiment 2 measured speech-to-masker ratios at threshold as a function of time-compression of the speech (0, 33, and 50%) in both maskers. Study sample: Participants were normal-hearing adults who were native speakers of Brazilian Portuguese (Experiment 1: N = 10; Experiment 2: N = 30). Results: The slope of the performance-intensity function was shallower in the modulated masker than in the steady masker for both words and sentences. Thresholds increased with increasing time-compression in both maskers, but more markedly in the modulated masker, resulting in reduced modulation masking release with increasing time-compression. Conclusions: Speech-to-masker ratio at threshold varies with time-compression of speech. The results are relevant to the issue of whether degree of masker modulation benefit depends on speech-to-masker ratio at threshold.     

Development of Scheelite Tailings-Based Ceramic Formulations with the Potential to Manufacture Porcelain Tiles,Semi-Stoneware and Stoneware

New ceramic formulations based on scheelite tailing were developed, and their potential in the ceramic industry was evaluated. Green bodies with different contents of scheelite tailing (0–8 wt%) were sintered (1150 °C, 1200 °C, and 1250 °C) and characterized in terms of the main mineralogical phases, microstructure, and physico-mechanical properties. The mullite was the main phase identified in all sintered temperatures. This result was also ratified with the aid of scanning electron microscope (SEM) images, in which small needles of the mullite were detected. The presence of mullite is required because it contributes to increasing the mechanical resistance of the material. The physico-mechanical properties measured (water absorption, linear shrinkage, apparent porosity, and flexural strength) were compared to the ISO 13006, and the samples sintered at 1150 °C presented potential to be used as semi-stoneware, while those sintered at 1200 °C and 1250 °C can be employed stoneware and porcelain tiles, respectively.     

Edentulousness in relation to remodeling of the gonial angles and incisures in dentate and edentate mandibles: morphometric study using the Image J software

Purpose

The human mandible is subject to stimuli during its growth phase and also in adulthood. One of these stimuli may be absence of teeth, which gives rise to mandibular remodeling. Morphological changes may occur in different areas of this bone, such as in the gonial, condylar and ramus regions.

Objective

To investigate the influence of edentulousness on remodeling of the gonial angle of the mandible and the angle formed by the mandibular incisure.

Materials and method

Eighty-five dry mandibles from adults were examined: 42 from males and 43 from females. The mandibles were photographed using a camera coupled to a static support that was positioned 20 cm from the object to be photographed. The images were digitized and transferred to the Image J 1.42q software, in which the gonial angle of the mandible and the mandibular incisure angle were measured.

Results

There were no differences in the mandibular and mandibular incisure angles in relation to presence or absence of teeth, or between the right and left sides. The mandibular incisure angle was greater in the women.

Conclusion

Edentulousness did not cause remodeling of the gonial angle of the mandible or in the mandibular incisure angle.     

Rutin-modified silver nanoparticles as a chromogenic probe for the selective detection of Fe3+ in aqueous medium

The development of nanoprobes for selective detection of metal ions in solution has attracted great attention due to their impact on living organisms. As a contribution to this field, this paper reports the synthesis of silver nanoparticles modified with rutin in the presence of ascorbic acid and their successful use as a chromogenic probe for the selective detection of Fe³⁺ in aqueous solution. Limits of detection and quantification were found to be 17 nmol L⁻¹ and 56 nmol L⁻¹, respectively. The sensing ability is proposed to proceed via an iron-induced nanoparticle growth/aggregation mechanism. A practical approach using image analysis for quantification of Fe³⁺ is also described.

The use of rutin-modified silver nanoparticles for selective detection and sensitive quantification of Fe³⁺ in aqueous solution is described.

Metal ions are key species in nature due to their essential functions in living organisms.^1,2 On the other hand, heavy metals as well as essential metals at abnormally high levels are toxic.² Iron, for instance, in addition to its popular use in industry and construction, is essential to the human body and active in biological processes. Although the trivalent form of iron is particularly important for oxygen transport in blood and the mitochondrial respiratory chain, high levels of this cation are associated with important pathologies.^3,4 The detection of metal ions in aqueous solution is traditionally performed by methods including atomic absorption spectrometry,⁵ electrochemical measurements,^6,7 and inductively coupled plasma techniques,⁸ among others. However, these techniques have important drawbacks, notably the need for sophisticated instrumentation, in addition to being time-consuming and requiring laborious procedures. To overcome these issues, the development of chromogenic and fluorogenic chemosensors for the selective detection of metal-targets has attracted great attention, especially due to the possibility of fast, sensitive and non-expensive analysis.^9,10 In the last decade, nanoscaled materials have been reported as selective probes for metal ions, including Fe³⁺.^11–24Silver nanoparticles (AgNPs) are of particular interest because of the affordable price of starting materials, ease of controlling size and morphology, possibility to functionalize their surface with organic molecules, and optical properties that enable detection of a variety of analytes via simple UV-vis spectroscopy and digital image analysis. Furthermore, applications of AgNPs are also biotechnologically relevant due to the possibility of green synthetic protocols, including the use of plant extracts,²⁵ natural sources,²⁶ glycerol,²⁷ among others.Flavonoids are secondary metabolites naturally found in fruits and other vegetables with relevant roles due to their nutritional, pharmaceutical and medicinal properties.²⁸ Because of their adequate structural features, flavonoids are candidates to be employed in the synthesis of AgNPs.²⁶ Rutin (RU), a sugar-based flavonoid, may be employed as reducing agent in the synthesis of AgNPs along with a stabilizer such as polyvinylpyrrolidone (PVP)²⁶ or used as crude plant extract component.^29,30This paper reports the use of RU-modified AgNPs (RU-AgNPs) as a chromogenic probe for Fe³⁺ in aqueous medium in the presence of ascorbic acid (AA). Sensing ability of RU-AgNPs for the selective detection of Fe³⁺ toward other metal cations was investigated with UV-vis spectroscopy analysis. These data and transmission electronic microscopy (TEM) results allowed a mechanistic proposal involved in the selective detection of Fe³⁺ by RU-AgNPs. Furthermore, a practical approach based on correlation of images of solutions obtained with a conventional smartphone and chemometrics was employed for a simpler quantification of Fe³⁺ in aqueous medium.Initially, the order of reagent combination was investigated in the synthesis of RU-AgNPs. Concentration of RU ranged from 0.10 to 0.50 mmol L⁻¹, while concentrations of other components were fixed at 0.20 mmol L⁻¹ AgNO₃, 0.10 mmol L⁻¹ AA and 0.10 M NaOH. Water was used as solvent in all cases. Narrower surface plasmon resonance (SPR) bands were obtained from adding a solution of AA and NaOH to a solution containing RU and AgNO₃ (Fig. 1a) against the addition of RU, AA, and NaOH to AgNO₃ solution (Fig. S1a – ESI^†), or the addition of RU and NaOH to a solution of AA and AgNO₃ (Fig. S1b^†). RU-AgNPs obtained from the condition presented in Fig. 1a are small (4.1 nm average diameter) and considerably polydisperse (standard deviation of 4.7 nm), however, presenting only one population (Fig. 1b and S2^†). A study of the influence of RU concentration (0.10 to 0.50 mmol L⁻¹) on the stability of RU-AgNPs over time indicated that 0.10 mmol L⁻¹ RU generates more stable RU-AgNPs (Fig. S3^†). Next, a study on the influence of pH indicated that RU-AgNPs are only stable under strong alkaline conditions (pH 12.5 or higher) (Fig. S4^†).Open in a separate windowFig. 1(a) UV-vis analysis of RU-AgNPs under strong alkaline condition (pH > 12.5) based on the order of adding reagents (RU, 0.10 to 0.50 mmol L⁻¹; AgNO₃, 0.20 mmol L⁻¹; AA, 0.10 mmol L⁻¹; NaOH, 0.10 mmol L⁻¹); (b) TEM image of RU-AgNPs under the selected condition.The ability of RU-AgNPs to sense metal cations was investigated by both naked-eye and UV-vis spectroscopy analysis (Fig. 2). The separate addition of 10 μmol L⁻¹ of several metal cations (Fe³⁺, Co²⁺, Zn²⁺, Sr²⁺, Cu²⁺. Al³⁺, Ba²⁺, Cd²⁺, Pb²⁺, Ni²⁺, Mg²⁺, Hg²⁺, Cu⁺ and Cr³⁺) to solutions of RU-AgNPs (prepared according to Fig. 1a) indicated that only Fe³⁺ induces a significant colorimetric change in the final aspect of solution after 50 minutes (Fig. 2a).Open in a separate windowFig. 2Naked-eye (a) and UV-vis (b) analysis of RU-AgNPs in absence (control, C) and presence of 10 μmol L⁻¹ of selected metal cations (Fe³⁺, Co²⁺, Zn²⁺, Sr²⁺, Cu²⁺. Al³⁺, Ba²⁺, Cd²⁺, Pb²⁺, Ni²⁺, Mg²⁺, Hg²⁺, Cu⁺ and Cr³⁺) after 50 min; (c) calibration curve obtained by the addition of different amounts (0 to 10 μmol L⁻¹) of Fe³⁺ to solutions of RU-AgNPs; (d) TEM image of RU-AgNPs after addition of Fe³⁺ (10 μmol L⁻¹). In all experiments, RU-AgNPs were prepared in the presence of ascorbic acid.The results presented in Fig. 2a are consistent with the UV-vis spectroscopy analysis (Fig. 2b). Co²⁺ ions also induce some change in the system, however at a considerably smaller extension than Fe³⁺. In this study, AA played a crucial role in the selective detection of Fe³⁺ by the referred nanoprobe. In the absence of AA, Co²⁺ (mainly) as well as other cations induce stronger colorimetric and spectral changes (Fig. S5a and b,^† respectively) in the analysis of solutions of RU-AgNPs when compared to the system containing AA. This selectivity may arise from two possible reasons: (i) preservation of RU by avoiding its oxidation in the reduction of Ag⁺ ions; (ii) coordination of ascorbate anion to cations other than Fe³⁺.Interaction of RU-AgNPs and Fe³⁺ (10 μmol L⁻¹) stabilizes after approximately 40 minutes (Fig. S6^†). Next, a calibration curve was built from the direct relationship between the absorbance at 396 nm and the concentration of Fe³⁺ (Fig. 2c), presenting a good correlation (R² = 0.9929). The limits of detection and quantification were found to be 17 nmol L⁻¹ and 56 nmol L⁻¹, respectively, which is very satisfactory.^13,14 The influence of other cations in the detection of Fe³⁺ was investigated by UV-vis spectroscopy. Fig. S7^† clearly demonstrates that there are only small changes when a second cation (30 μmol L⁻¹) is added together with Fe³⁺ to the RU-AgNPs solution.Mechanistically, the detection of Fe³⁺ by RU-AgNPs in aqueous medium proceeds via a growth/aggregation-combined process. This proposal is first evidenced by UV-vis analysis due the suppression of SPR band (Fig. 2b), a behavior consistent with the literature.^31,32 Interestingly, TEM analysis clearly shows a growth in AgNPs size after addition of Fe³⁺ to the solution (Fig. 2d), resulting in a final single AgNPs population with average diameter of 14.7 nm ± 8.9 nm. Due to the strong alkaline medium, the main specie responsible for the behavior of NPs is likely to be Fe(OH)₃. A schematic illustration of the mechanism involving aggregation of RU-AgNPs induced by the addition of Fe³⁺ is presented in Fig. 3. AgNPs are initially formed by adsorption of anionic RU to the silver surface via deprotonated 5-hydroxychromen-4-one moiety. This is supported by the literature³³ and confirmed by alteration in the 1800–1500 cm⁻¹ region of the RU infrared spectra before and after coordination with silver (Fig. S9^†). Afterwards, the addition of Fe³⁺ induces the formation of a coordination complex through an anionic catechol group, in which at least 2 : 1 ligand–Fe³⁺ stoichiometry is required for an aggregated effect.Open in a separate windowFig. 3Mechanistic proposal for growth/aggregation of RU-AgNPs in the presence of Fe³⁺. Insert: binding model for RU-AgNPs.Due to increasing interest in image processing as an analytical tool for many purposes,^34,35 Multiple Linear Regression was employed to verify the capacity of the RU-AgNPs to probe Fe³⁺ standards at distinct concentrations, as presented in Fig. 4. The curve was obtained by plotting the color absorbances RGB-based values versus the concentrations of Fe³⁺ standards after RU-AgNPs interaction. Predicted iron is a vector based on RGB values that were then extracted from the filtered images and inserted in the equation described by Beer–Lambert law in order to generate the absorbances for the construction of the analytical curve. A linear behavior between the predicted response and the measured concentrations was observed (R² = 0.9806).Open in a separate windowFig. 4Calibration curve for Fe³⁺ analysis showing the predicted iron (RGB) vs. iron(iii) concentration (1 to 8 μmol L⁻¹). Adjusted R² = 0.9806.Regression coefficients of the calibration model (using the R, G and B channels simultaneously) obtained by MLR method are shown in eqn (1):[Fe³⁺] = 44.5R − 4.9G − 16.4B + 5.11where Fe³⁺ concentration is the dependent variable (Predicted Iron), 5.1 is the intercept (β₀), 44.5, −4.9 and −16.4 are the regression coefficients of the independent variables (R, G and B channels, respectively).It is possible to observe an interesting performance of the method using the three RGB color channels allied with MLR to quantify the Fe³⁺ content, which presented reasonable deviations in its responses considering that it is simple and low-cost. The good linearity is similar to other colorimetric methods such as sodium determination in seawater and coconut water (R² > 0.91) by Moraes and coauthors,³⁶ or iron(ii) in simulated seawater (R² = 0.9993) by Gasparotto et al.³⁷Second order regression was applied to the dataset to obtain a better adjustment, resulting in an adjusted R-squared of 0.9955. RGB values were then inserted in eqn (2) in order to generate the construction of the correlation:[Fe³⁺] = 14.4R + 30.7G − 23.4B − 398RG − 348RB − 0.8BG − 978R² + 695G² + 26.9B² + 4.52This paper reports the use of AgNPs functionalized with RU as nanoprobes for selective detection and sensitive quantification of Fe³⁺ in aqueous solution. The synthesis of RU-AgNPs is reproducible, easily performed and requires no stabilizer agent other than RU. AA has a crucial role in the selectivity by either the avoidance of oxidation of RU by silver and/or coordination of ascorbate with other cations. The literature brings relevant examples of chromogenic and fluorogenic chemosensors for selective detection of Fe³⁺ in solution. Many of these artificial organic receptors present high selectivity and relevant limits of detection, requiring, however, very specific reagents and laborious synthetic procedures.^38–41 Metal-based nanoparticles have emerged as potential probes for detection of Fe³⁺.^11–16 Although effective in Fe³⁺ sensing, the synthesis of these nanoprobes require some toxic reagents, such as NaBH₄ or PVP, use plant extracts, which may lead to some drawbacks, such as the understanding of the sensing mechanism. In contrast, our method is based on commercially available, nontoxic, low-cost reagents. Fe³⁺ sensing performed satisfactorily in the 1–10 μmol L⁻¹ range, and the limit of detection obtained with this method (17 nmol L⁻¹) is comparable to the most sensitive methods reported in literature. A mechanism for the detection of Fe³⁺ by RU-AgNPs involves a combined growth/aggregation of the NPs. There is a still limited number of nanoscaled systems reported as being selective and sensitive in the detection of Fe³⁺, which reinforces the relevance of the method reported herein. The linearity range obtained by both UV-vis spectroscopy and image analysis comprises the maximum of residual Fe³⁺ in drinking water according to the European and US legislations.^15,42     

Percutaneous radiofrequency ablation for early hepatocellular carcinoma: Risk factors for survival

AIM: To evaluate outcomes of radiofrequency ablation(RFA) therapy for early hepatocellular carcinoma(HCC) and identify survival- and recurrence-related factors. METHODS: Consecutive patients diagnosed with early HCC by computed tomography(CT) or magnetic resonance imaging(MRI)(single nodule of ≤ 5 cm, or multi-(up to 3) nodules of ≤ 3 cm each) and who underwent RFA treatment with curative intent between January 2010 and August 2011 at the Instituto do Cancer do Estado de S o Paulo, Brazil were enrolled in the study. RFA of the liver tumors(with 1.0 cm ablative margin) was carried out under CT-fluoro scan and ultrasonic image guidance of the percutaneous ablation probes. Procedure-related complications were recorded. At 1-mo post-RFA and 3-mo intervals thereafter, CT and MRI were performed to assess outcomes of complete response(absence of enhancing tissue at the tumor site) or incomplete response(enhancing tissue remaining at the tumor site). Overall survival and diseasefree survival rates were estimated by the Kaplan-Meier method and compared by the log rank test or simple Cox regression. The effect of risk factors on survival was assessed by the Cox proportional hazard model. RESULTS: A total of 38 RFA sessions were performed during the study period on 34 patients(age in years: mean, 63 and range, 49-84). The mean follow-up time was 22 mo(range, 1-33). The study population showed predominance of male sex(76%), less severe liver disease(Child-Pugh A, n = 26; Child-Pugh B, n = 8), and single tumor(65%). The maximum tumor diameters ranged from 10 to 50 mm(median, 26 mm). The initial(immediately post-procedure) rate of RFAinduced complete tumor necrosis was 90%. The probability of achieving complete response was significantly greater in patients with a single nodule(vs patients with multi-nodules, P = 0.04). Two patients experienced major complications, including acute pulmonary edema(resolved with intervention) and intestinal perforation(led to death). The 1- and 2-year overall survival rates were 82% and 71%, respectively. Sex, tumor size, initial response, and recurrence status influenced survival, but did not reach the threshold of statistical significance. Child-Pugh class and the model for end-stage liver disease score were identified as predictors of survival by simple Cox regression, but only Child-Pugh class showed a statistically significant association to survival in multiple Cox regression analysis(HR = 15; 95%CI: 3-76 mo; P = 0.001). The 1-and 2-year cumulative disease-free survival rates were 65% and 36%, respectively. CONCLUSION: RFA is an effective therapy for local tumor control of early HCC, and patients with preserved liver function are the best candidates.     

Cardiac Rehabilitation in the United States

Coronary heart disease (CHD) is a significant cause of morbidity and mortality in the United States (US). In addition to this, many of the risk factors of CHD, such as obesity, sedentary lifestyle, diabetes mellitus, and poor nutrition, are disproportionately high in the US. Despite the many known benefits of cardiac rehabilitation (CR), referral and participation rates in these programs are paradoxically low. Over the course of this review, we will discuss some of the many benefits of CR, some of the risk factors for CHD in the US, and factors that affect referral and participation in these programs.