Emerging and re-emerging infectious diseases: a biological evolutionary drama

Cervical intraepithelial neoplasia grade 3 (CIN 3) is treated surgically. Follow-up of these patients is important to ensure successful treatment. The present study was undertaken to determine whether human papillomavirus (HPV) testing can be used to discriminate patients who will have recurrences from those who will not. It is composed of 26 patients who presented with recurrences of CIN and 22 patients who remained disease-free after treatment. DNA was extracted from paraffin-embedded cone biopsies of incident CIN 3, their corresponding follow-up Pap smears taken 3 months postoperatively, and their secondary cone biopsies of the recurrent lesions. The extracted DNA were then analyzed by PCR for the presence of HPV. The posttreatment cervical smears in the recurrent group had a (25/26) 96% HPV prevalence, while HPV DNA was not detectable in any of the 22 patients in the control group. The HPV types in both the initial and recurrent lesions correlated very well. This suggest that most recurrences are likely to be due to persisting lesions or subclinical HPV infections that had not been completely removed. Cytology alone was not sufficiently sensitive to discriminate the patients at risk for recurrences. It appears that HPV testing can be useful to monitor the therapeutic result.     

Digital ischemia and gangrene due to red blood cell aggregation induced by acquired dysfibrinogenemia

Digital gangrene was observed in a patient who had angiographic findings of digital arterial occlusion. The patient's blood showed a marked red blood cell aggregation with rouleaux formation in long chains, which could not be dispersed at shear rates up to 200 sec-1. Studies of the patient's blood revealed the presence of an abnormal fibrinogen capable of aggregating normal red blood cells. This fibrinogen was found by Raman spectroscopy to have an increased alpha-helical content, whereas the beta-sheet content was decreased. Defibrinogenation therapy with ancrod resulted in a dramatic symptomatic relief. The disappearance of the abnormal fibrinogen 6 months later and an absence of a family history indicate that this dysfibrinogenemia was acquired.     

具有联网功能的家用设备

现在,人人都能使用互联网,它具有采集新闻和内容共享到实时通信多种多样的用途.这些活动主要通过个人计算机和智能手机实现,而在家里联网电视已开始担当这个角色.     

Development of non-enzymatic ZnO nanocomposite-based optical sensor for l-lactate detection in tomato samples

l -lactate is a conjugate base of α-hydroxy acid, a key organic chemical in food processing, fermentation, biology and chemical industries. We are reporting for the first time a facile and rapid non-enzymatic nanosensor for l -lactate detection in tomato-based products using 3-aminophenylboronic acid (3-APBA)-added zinc oxide nanoparticles (ZnO NPs). 3-APBA-functionalised ZnO NPs have a selective and stable SPR intensity change at pH 5.5 to 7.5 and forms a reversible ester with bound l -lactate revealing the wavelength shift from λ = 300 nm to 288 nm in UV-VIS absorption spectrometry. In the spiked (2.5–20 mm ) samples of tomato puree, absorption peak increased as per l -lactate addition with the lower detection limit of 3.98 mm . l -lactate binds with a trigonal form of 3-boronate, thereby generating the tetrahedral complex. ZnO NPs stabilise the tetragonal complex. Nanosensor validated with standard HPLC. This method is useful for l -lactate detection and alternates to conventional techniques.     

Precision Nanocluster-Based Toroidal and Supertoroidal Frameworks Using Photocycloaddition-Assisted Dynamic Covalent Chemistry

Atomically precise nanoclusters (NCs) have recently emerged as ideal building blocks for constructing self-assembled multifunctional superstructures. The existing structures are based on various non-covalent interactions of the ligands on the NC surface, resulting in inter-NC interactions. Despite recent demonstrations on light-induced reversible self-assembly, long-range reversible self-assembly based on dynamic covalent chemistry on the NC surface has yet to be investigated. Here, it is shown that Au₂₅ NCs containing thiolated umbelliferone (7-hydroxycoumarin) ligands allow [2+2] photocycloaddition reaction-induced self-assembly into colloidal-level toroids. The toroids upon further irradiation undergo inter-toroidal reaction resulting in macroscopic supertoroidal honey-comb frameworks. Systematic investigation using electron microscopy, atomic force microscopy (AFM), and electron tomography (ET) suggest that the NCs initially form spherical aggregates. The spherical structures further undergo fusion resulting in toroid formation. Finally, the toroids fuse into macroscopic honeycomb frameworks. As a proof-of-concept, a cross-photocycloaddition reaction between coumarin-tethered NCs and an anticancer drug (5-fluorouracil) is demonstrated as a model photo-controlled drug release system. The model system allows systematic loading and unloading of the drug during the assembly and disassembly under two different wavelengths. The results suggest that the dynamic covalent chemistry on the NC surface offers a facile route for hierarchical multifunctional frameworks and photocontrolled drug release.     

Fabrication and testing of natural fibre composites: Vakka, sisal, bamboo and banana

A study has been carried out to investigate the tensile, flexural and dielectric properties of composites made by reinforcing vakka as a new natural fibre into a polyester resin matrix. The fibres extracted by retting and manual processes have been used to fabricate the composites. These composites are tested for tensile, flexural and dielectric properties and compared with those of established composites like sisal, bamboo and banana made under the same laboratory conditions. The composites are fabricated up to a maximum volume fraction of fibre of 0.37 in the case of tensile testing, and 0.39 for flexural and dielectric testing. It has been observed that the tensile properties increase with respect to volume fraction of fibre for vakka fibre composite and are also more than those of sisal and banana composites and comparable to those of bamboo composites. The flexural strength of vakka fibre composite is more than that of banana composite and is closer to sisal fibre composite with respect to the volume fraction of fibre, where as the flexural modulus is much higher than those of banana and sisal fibre composites and also very much closer to bamboo fibre composites. The dielectric strength of vakka fibre composite increases with increase in volume fraction of fibre in the composite unlike the case of sisal, bamboo and banana composites. The dielectric strength being a unique feature of vakka fibre composite, can be suggested for electrical insulation applications.