New Device for Intrinsic Hand Muscle Strength Measurement: An Alternative to Strain Gauge Handheld Dynamometer

© The Author(s) 2017. An accurate measurement of intrinsic hand muscle strength (IHMS) is required by clinicians for effective clinical decision-making, diagnosis of certain diseases, and evaluation of the outcome of treatment. In practice, the clinicians use Intrins-o-meter and Rotterdam Intrinsic Hand Myometer for IHMS measurement. These are quite bulky, expensive, and possess poor interobserver reliability (37–52%) and sensitivity. The purpose of this study was to develop an alternative lightweight, accurate, cost-effective force measurement device with a simple electronic circuit and test its suitability for IHMS measurement. The device was constructed with ketjenblack/deproteinized natural rubber sensor, 1-MΩ potential divider, and Arduino Uno through the custom-written software. Then, the device was calibrated and tested for accuracy and repeatability within the force range of finger muscles (100 N). The 95% limit of agreement in accuracy from −1.95 N to 2.06 N for 10 to 100 N applied load and repeatability coefficient of ±1.91 N or 6.2% was achieved. Furthermore, the expenditure for the device construction was around US$ 53. For a practical demonstration, the device was tested among 16 participants for isometric strength measurement of the ulnar abductor and dorsal interossei. The results revealed that the performance of the device was suitable for IHMS measurement

IP6 is an HIV pocket factor that prevents capsid collapse and promotes DNA synthesis.

The HIV capsid is semipermeable and covered in electropositive pores that are essential for viral DNA synthesis and infection. Here, we show that these pores bind the abundant cellular polyanion IP6, transforming viral stability from minutes to hours and allowing newly synthesised DNA to accumulate inside the capsid. An arginine ring within the pore coordinates IP6, which strengthens capsid hexamers by almost 10°C. Single molecule measurements demonstrate that this renders native HIV capsids highly stable and protected from spontaneous collapse. Moreover, encapsidated reverse transcription assays reveal that, once stabilised by IP6, the accumulation of new viral DNA inside the capsid increases >100 fold. Remarkably, isotopic labelling of inositol in virus-producing cells reveals that HIV selectively packages over 300 IP6 molecules per infectious virion. We propose that HIV recruits IP6 to regulate capsid stability and uncoating, analogous to picornavirus pocket factors. HIV-1/IP6/capsid/co-factor/reverse transcription

Enhanced wide-range monotonic piezoresistivity, reliability of Ketjenblack/deproteinized natural rubber nanocomposite, and its biomedical application

Piezoresistive behavior of 6 to 9 wt % Ketjenblack-reinforced deproteinized natural rubber (KB/DPNR) nanocomposite developed by two-roll mill was studied under compressive pressure (0 to 12.54 MPa). The 6 wt % KB/DPNR exhibited monotonic piezoresistivity, the highest electrical resistance change (485%), remarkable reversibility and minimal hysteresis. Furthermore, a good sensitivity (S) = 1.1 MPa−1 for 0.25 to 2.49 MPa, high test–retest reliability (intraclass correlation co-efficient, ICC = 0.99) under 0 to 2.49 MPa for three repetitions conducted at an interval of 24 h and excellent repeatability (standard deviation, SD = 4.8%) to a swing of 6.25 MPa for 50 cyclic compression were achieved. Homogeneous dispersion and high aspect ratio of KB and higher chemical linkage (due to double crosslinking agents) between KB and DPNR may be responsible for the enhanced piezoresistivity. For practical application, the KB/DPNR was interfaced with the microcontroller through a bridge rectifier via custom-built Simulink and successfully monitored finger pressure in real time during bone movement on human