Improved protocol for plasma microRNA extraction and comparison of commercial kits

IntroductionMicroRNAs are small, non-coding RNA molecules that are becoming popular biomarkers in several diseases. However, their low abundance in serum/plasma poses a challenge in exploiting their potential in clinics. Several commercial kits are available for rapid isolation of microRNA from plasma. However, reports guiding the selection of appropriate kits to study downstream assays are scarce. Hence, we compared four commercial kits to evaluate microRNA-extraction from plasma and provided a modified protocol that further improved the superior kit’s performance.Materials and methodsWe compared four kits (miRNeasy Serum/Plasma, miRNeasy Mini Kit from Qiagen; RNA-isolation, and Absolutely-RNA MicroRNA Kit from Agilent technologies) for quality and quantity of microRNA isolated, extraction efficiency, and cost-effectiveness. Bioanalyzer-based Agilent Small RNA kit was used to evaluate quality and quantity of microRNA. Extraction efficiency was evaluated by detection of four endogenous control microRNA using real-time-PCR. Further, we modified the manufacturer’s protocol for miRNeasy Serum/Plasma kit to improve yield.ResultsmiRNeasy Serum/Plasma kit outperformed the other three kits in microRNA-quality (P < 0.005) and yielded maximum microRNA-quantity. Recovery of endogenous control microRNA i.e. hsa-miR-24-3p, hsa-miR-191-5p, hsa-miR-423-5p and hsa-miR-484 was higher as well. Modification with the inclusion of a double elution step enhanced yield of microRNA extracted with miRNeasy Serum/Plasma kit significantly (P < 0.001).ConclusionWe demonstrated that miRNeasy Serum/Plasma kit outperforms other kits and can be reliably used with a limited plasma quantity. We have provided a modified microRNA-extraction protocol with improved microRNA output for downstream analyses.     

Authorship conflict in Bangladesh: an exploratory study

This study aimed to explore the causes, types, and consequences of authorship conflicts among the researchers of selected research institutions in Dhaka, Bangladesh; and to suggest ways to reduce conflicts. A sample of 100 researchers was given a semi‐structured questionnaire; 45 subjects responded. The responses were confidential and anonymous. Over two‐thirds of the respondents were aware of authorship conflicts, and one‐third had actually faced conflicts with their co‐authors. Of them, four faced conflicts with their juniors, while 13 faced conflicts with their seniors or supervisors. The primary causes of such conflicts appear to be unethical claims of authorship, violation of authorship order, and deprivation of authorship. In most cases, the victims became frustrated and had to give up, and avoided a direct clash to safeguard their job. Four respondents claimed to have been victimized for raising their voice. Conflict was never resolved in seven cases. To reduce conflicts, respondents suggested that authorship should be decided before the study begins, order of authorship must be determined according to contribution, and a standard code of authorship should be followed strictly. Authorship conflicts arise among researchers mostly due to what they regard as unethical practice of their co‐authors, supervisors, and department heads in the absence of any formal authorship policy in the institutions. A standard code of authorship, sensitization of researchers to the problem through open discussions and advocacy, and formation of a grievance redress committee are suggested to minimize such conflicts. Although the sample size was small, some of the specific recommendations will be appropriate in many other cases.     

Using Hands-On and Virtual Laboratories Alone or Together―Which Works Better for Acquiring Knowledge and Skills?

Journal of Science Education and Technology - Although hands-on laboratory experiments are traditionally used in schools, virtual laboratories have entered today’s classrooms, due to their...     

Effectiveness of Computer-Based Chemistry Instruction in Enhancing the Learning of Content and Variable Control Under Guided Versus Unguided Conditions

Computerized learning environments offer several possibilities that can be used to improve the teaching of content along with the process. Research indicates that students benefit from additional guidance, particularly when computer-based instruction requires active construction of knowledge. This study examines the relative effectiveness of guided versus unguided computer-based instruction with respect to regular instruction in improving content knowledge and process skills among students with low and high chemistry achievement levels. The results indicate that the effectiveness of computer-based instruction increases when learning is supported by teacher-directed guidance. Computer-based instruction (with or without guidance) was observed to be more effective than regular instruction in improving process skills particularly for students with high chemistry achievement. However, although the students who received regular or guided computer-based instruction showed significant gains in content knowledge, students under unguided condition failed to construct the expected content knowledge.     

Time‐Limited Counseling Outcome in a Nationwide College Counseling Center Sample

This study examined the dose‐effect relationship between the number of sessions and therapeutic outcome in a large, nationwide counseling center research consortium. A positive relationship was found between the outcome of counseling and the number of sessions attended. The results of this study support the effectiveness of brief psychotherapy.     

记忆热力学关系式的状态函数正方形和Maxwell正方形

本文提出了状态函数正方形和Maxwell正方形的概念,提出了使用状态函数正方形和Maxwell正方形记忆热力学关系式方法.使用本方法可迅速记忆特性函数与特征变量的关系式、基本公式、对应系数的关系式和Maxwell关系式等20个热力学公式,而且不易忘记.     

Serum lipid profile in patients with acute myocardial infarction

Serum lipids and lipoproteins were estimated in 29 patients with acute myocardial infarction during acute phase (day 1,2,3), predischarge and after three months. Serum total lipids, total cholesterol (TC) and LDL-cholesterol (LDLc) showed no significant change during the hospital stay and three months followup. HDL-cholesterol (HDLc), however, started falling from day 2 onwards with statistically significant reduction at pre-discharge and remained so at 3 months. The ratios of TC/HDLc and LDLc/HDLc showed significant increase on predischarge day as compared to day 1. Serum triglycerides also showed an increasing trend after myocardial infarction with a significant increase on day 3 and predischarge as compared to day 1. it is concluded that the optimum time for assessment of serum lipid profile in patients with myocardial infarction seems to be within 24 hours of the acute episode.     

Effects of pelvis-shoulders torsional separation style on kinematic sequence in golf driving

The golfer’s body (trunk/arms/club) can be modeled as an inclined axle-chain system and the rotations of its parts observed on the functional swing plane (FSP) can represent the actual angular motions closely. The purpose of this study was to investigate the effects of pelvis-shoulders torsional separation style on the kinematic sequences employed by the axle-chain system in golf driving. Seventy-four male skilled golfers (handicap ≤ 3) were assigned to five groups based on their shoulder girdle motion and X-factor stretch characteristics: Late Shoulder Acceleration, Large Downswing Stretch, Large Backswing Stretch, Medium Total Stretch, and Small Total Stretch. Swing trials were captured by an optical system and the hip-line, thorax, shoulder-line, upper-lever, club, and wrist angular positions/velocities were calculated on the FSP. Kinematic sequences were established based on the timings of the peak angular velocities (backswing and downswing sequences) and the backswing-to-downswing transition time points (transition sequence). The backswing and transition sequences were somewhat consistent across the groups, showing full or partial proximal-to-distal sequences with minor variations. The downswing sequence was inconsistent across the groups and the angular velocity peaks of the body segments were not significantly separated. Various swing characteristics associated with the separation styles influenced the motion sequences.