Transmission of multidrug-resistant tuberculosis within family households by DTM-PCR and MIRU-VNTR genotyping.

BACKGROUND: Drug-resistant tuberculosis (TB) continues to be a public health threat. There are few studies on transmission and genotyping of MDR-TB family households in China. This study aimed to investigate transmission of multidrug-resistant tuberculosis (MDR-TB) within family households by deletion-targeted multiplex polymerase chain reaction (DTM-PCR), mycobacterial interspersed repetitive unit variable number tandem repeats (MIRU-VNTR) genotyping. METHODS: Among 993 MDR-TB patients registered from Wuhan Institute for Tuberculosis Control, drug resistance and the time interval between the index patients and secondary patients were analyzed in 49 MDR-TB patients from 23 families, in which 22 MDR-TB strains from 11 families who had matched strains were genotyped by DTM-PCR and standard 24-loci MIRU-VNTR genotyping method. RESULTS: The time interval between the index patients and the secondary patients ranged from half a month to 110 months. Thirteen secondary patients developed active MDR-TB within two years and accounted for 50% (13/26) of all secondary patients. Among eleven pairs of MDR-TB families, six pairs had identical genotypes, the cluster rate was 54.5% (12/22); three pairs had a single MIRU-VNTR locus variation. If a single MIRU-VNTR locus variation was tolerated in the cluster definition, the cluster rate raised to 81.8% (18/22). CONCLUSIONS: The family households of MDR-TB patients are at risk for infection of MDR-TB. To reduce transmission, MDR-TB patients should be diagnosed earlier and promptly treated in an effective manner, meanwhile, the close family contacts should be screened for TB infection.

Three-dimensional nanotubes composed of carbon-anchored ultrathin MoS2 nanosheets with enhanced lithium storage.

MoS2 nanotubes (denoted as MoS2 NTs) assembled from well-aligned amorphous carbon-modified ultrathin MoS2 nanosheets (denoted as MoS2 NT@C) were successfully fabricated via a facile solvothermal method combined with subsequent annealing treatment. With the assistance of octylamine as a solvent and carbon source, interconnected MoS2 nanosheets (denoted as MoS2 NSs) can assemble into hierarchical MoS2 NTs. Such a hybrid nanostructure can effectively facilitate charge transport and accommodate volume variation upon prolonged charge/discharge cycling for reversible lithium storage. As a result, the MoS2 NT@C composite manifests a very stable high reversible capacity of around 1351 mA h g(-1) at a current density of 100 mA g(-1); even after 150 cycles, the electrode reaches a capacity of 1106 mA h g(-1) and it retains a reversible capacity of 650 mA h g(-1) after the 10th cycle at a current density of 3 A g(-1), all of which indicate that the MoS2 NT@C nanocomposite is a promising negative electrode material for high-energy lithium ion batteries.

Polyacrylamide Hydrogel Composite E-skin Fully Mimicking Human Skin.

Transparent e-skin that can fully mimic human skin with J-shaped mechanical-behavior and tactile sensing attributes have not yet been reported. In this work, the skin-like hydrogel composite with J-shaped mechanical behavior and highly transparent, tactile, soft but strong, flexible, and stretchable attributes is developed as structural strain sensing element for e-skin. Piezo-resistive polyacrylamide (PAAm) hydrogel is used as supporting matrix to endow high transparency, softness, flexibility, stretch-ability and strain sensing capability desired for e-skin. Ultrahigh molecular weight polyethylene (UHMWPE) fiber with a wavy configuration is designed as reinforcement filler to provide the tunable strain-limiting effect. As a result, the as-prepared UHMWPE fiber/PAAm composite e-skin presents unique "J-shape" stress-strain behavior akin to human skin. And the PAAm composite can switch from supersoft to highly stiff in the designed strain range up to 100% with a prominent tensile strength of 48.3 MPa, which enables it to have the high stretch-ability and excellent load-bearing ability, simultaneously. Moreover, finite element model is developed to clarify the stress distribution and damage evolution for the UHMWPE fiber/PAAm composite during the tensile process. The PAAm composite exhibits not only an excellent strain sensing performance with a long-term reliability up to 5000 loading-unloading cycles but also an extraordinary softness and mechanical strength with a low initial modulus of 6.7 kPa, which is matchable with soft human epidermis. Finally, the e-skin is used for demonstrations in monitoring various human activities and protecting structural integrity in designed strain ranges. The strategy for reinforcing piezo-resistive hydrogel with wavy-shaped UHMWPE fibers proposed here is promising for the development of transparent, flexible, soft but strong e-skin with a tunable strain-limiting effect akin to human skin.

Bioinspired Color-Changeable Organogel Tactile Sensor with Excellent Overall Performance.

Inspired by chameleons' structural color regulation capability, a simple, but effective, swelling method is proposed for the first time to prepare an ionic polyacrylamide (PAAm) organogel for simultaneous tactile sensing and interactive color changing. The PAAm organogel obtained by swelling the PAAm scaffold in the dimethyl sulfoxide solution of organic electrochromic material (OECM) shows an extremely large stretchability with an elongation of 1600%, a supersoftness with a compressive modulus of 7.2 kPa, an excellent transmittance up to 90%, and a very fast response time of 0.5 s combined with the characteristic of interactive color changing. The PAAm organogel also suggests a universal design ability to tailor coloration spectra for tactile sensors via simply changing the type and content of OECM. The tactile sensor based on a PAAm organogel is capable of serving as a wearable device for precisely tracing human body motion performance and directly visualizing the stress distribution via interactive color changing capability. It is demonstrated that the swelling method proposed here is a simple and practical strategy to prepare ionic organogels with both piezo-resistive and electrochromic effects.

Hepatocellular adenoma: comparison between real-time contrast-enhanced ultrasound and dynamic computed tomography.

PURPOSE: To investigate and compare the contrast-enhanced ultrasound (CEUS) features of histologically proven HCA with those of contrast-enhanced computed tomography (CECT). METHODS: Eighteen patients with proven hepatic adenoma by pathology were retrospectively selected from the CEUS database. Fourteen of them had undergone liver CECT exams. The basic features on unenhanced imaging and the enhancement level and specific features on contrast-enhanced imaging were retrospectively analyzed, and the differences between CEUS and CECT were compared. RESULTS: All the HCAs showed hyper-enhancement in the arterial phase. During the portal and late phases, 12 HCAs (12/18, 66.7 %) on CEUS and 11 (11/14, 78.6 %) on CT showed washout. On CEUS, 10 (10/18, 55.5 %) showed centripetal filling in the arterial phase and persistent peripheral rim enhancement. Five of them (61.1 %, 11/18) showed delayed central washout in the portal or late phase. However, on CECT, 2 (14.3 %, 2/14) and 4 (28.6 %, 4/14) HCAs showed persistent enhancement of the peripheral rim and central non-enhancing hemorrhage areas, respectively. CONCLUSIONS: Compared with dynamic CT, CEUS was superior at characterizing specific dynamic features. Considering that it is radiation-free, readily availability and easy to use, CEUS is suggested as the first line imaging tool to diagnose HCA.

Facile Synthesis of Novel Networked Ultralong Cobalt Sulfide Nanotubes and Its Application in Supercapacitors.

Ultralong cobalt sulfide (CoS(1.097)) nanotube networks are synthesized by a simple one-step solvothermal method without any surfactant or template. A possible formation mechanism for the growth processes is proposed. Owing to the hollow structure and large specific area, the novel CoS(1.097) materials present outstanding electrochemical properties. Electrochemical measurements for supercapacitors show that the as-prepared ultralong CoS(1.097) nanotube networks exhibit high specific capacity, good capacity retention, and excellent Coulombic efficiency.