High-resolution cost-effective compact portable inverted light microscope.

Commercial high-resolution optical microscopes are essential for microscopy imaging; however, they are expensive and bulky, which limits their use in point-of-care devices, resource-limited areas, and real-time imaging of a sample in a large apparatus. In this study, we report a novel compact (10 cm × 5 cm × 5 cm, without the light source) lightweight (∼0.5 kg) submicron-resolution inverted optical microscope at low cost (∼$ 300). Our technique utilises the proximity of the image sensor to a commercial microscope objective lens for compactness of the microscope. The use of an image sensor with a small pixel size helps to reduce the information loss, which provides high-resolution images. Moreover, our technique offers a freedom to tailor the design of microscope according to the required resolution, cost, and portability for specific applications, which makes it a suitable candidate for affordable point-of-care devices. Images of several micron-to-submicron scale patterns and spherical beads are acquired to observe the resolution and quality of the images obtained using our microscope. In addition, we demonstrate the applications of our microscope in various fields such as recording of high-speed water microdroplet formation inside a microfluidic device, high-resolution live cell imaging inside an incubator, and real-time imaging of crack propagation in a sample under stretching by a material testing system (MTS). Therefore, this portable and inexpensive microscope provides the essential functionalities of a bulky expensive high-performance microscope at a lower cost. LAY DESCRIPTION: Microscope is an essential tool in research allowing for observation of microsized objects and life forms. Contemporary commercial high-resolution microscopes have long optical paths involving series of lenses and filters. Although this configuration precisely corrects for optical distortions and produces clear images, it makes modern microscopes very costly and bulky, restricting their usage to low-funded research laboratories and at remote places. We have developed a simple digital microscope with high-resolution but with much smaller size and lighter in weight at low cost by removing the long optical terrain. Our microscope consists of a commercial microscope objective lens for magnification and semiconductor image sensor with small pixels placed right after the lens, both of which are affordable and easily available. The small pixel size helps to translate the magnified analogue sample image to high-resolution digital image. In our paper, we show that our microscope can view micro and submicron-sized patterns and beads. Moreover, our fist-sized microscope can be placed inside an incubator for real-time imaging of cells or rotated sideways for recording submicron-sized crack generation due stretching of novel materials, both of which could not be accomplished with the 2 feet tall laboratory microscopes.

Accelerating access to quality TB care for pediatric TB cases through better diagnostic strategy in four major cities of India.

BACKGROUND: Diagnosis of TB in children is challenging, and is largely based on positive history of contact with a TB case, clinical and radiological findings, often without microbiological confirmation. Diagnostic efforts are also undermined by challenges in specimen collection and the limited availability of high sensitivity, rapid diagnostic tests that can be applied with a quick turnaround time. The current project was undertaken in four major cities of India to address TB diagnostic challenges in pediatric population, by offering free of cost Xpert testing to pediatric presumptive TB cases, thereby paving the way for better TB care. METHODS: A high throughput lab was established in each of the four project cities, and linked to various health care providers across the city through rapid specimen transportation and electronic reporting linkages. Free Xpert testing was offered to all pediatric (0-14 years) presumptive TB cases (both pulmonary and extra-pulmonary) seeking care at public and private health facilities. RESULTS: The current project enrolled 42,238 pediatric presumptive TB cases from April, 2014 to June, 2016. A total of 3,340 (7.91%, CI 7.65-8.17) bacteriologically confirmed TB cases were detected, of which 295 (8.83%, CI 7.9-9.86) were rifampicin-resistant. The level of rifampicin resistance in the project cohort was high. Overall Xpert yielded a high proportion of valid results and TB detection rates were more than three-fold higher than smear microscopy. The project provided same-day testing and early availability of results led to rapid treatment initiation and success rates and very low rates of treatment failure and loss to follow-up. CONCLUSION: The current project demonstrated the feasibility of rolling out rapid and upfront Xpert testing for pediatric presumptive TB cases through a single Xpert lab per city in an efficient manner. Rapid turnaround testing time facilitated prompt and appropriate treatment initiation. These results suggest that the upfront Xpert assay is a promising solution to address TB diagnosis in children. The high levels of rifampicin resistance detected in presumptive pediatric TB patients tested under the project are a major cause of concern from a public health perspective which underscores the need to further prioritize upfront Xpert access to this vulnerable population.

Mannose and galactose as substrates for production of itaconic acid by Aspergillus terreus.

Itaconic acid (IA), an unsaturated 5-carbon dicarboxylic acid, is a building block platform chemical that is currently produced industrially from glucose by fermentation with Aspergillus terreus. Softwood has the potential to serve as low cost source of sugars for its production. Effective utilization of all softwood derived sugars such as glucose, mannose and galactose by the fungus for production of IA will lower the cost of its production. In this work, 20 A. terreus strains were evaluated for the first time for IA production from mannose and galactose in shake-flasks at initial pH of 3·1, 33°C and 200 rev min-1 for 7 days. Strain NRRL 1971 possesses the unique ability to produce high concentrations of IA from mannose. It produced 36·4 ± 0·2 g IA from 80 g mannose per litre with a yield of 0·46 g g-1 mannose (highest titre reported so far). This strain has the potential to be used for IA production from softwood. The maximum (1·1 ± 0·2 g) IA was produced by strain DSM 23081 from 80 g galactose per litre utilizing only 9·1 ± 0·3 g. Galactose was not suitable for IA production by these strains. This is the first detailed report on the production of IA from mannose and galactose. SIGNIFICANCE AND IMPACT OF THE STUDY: Itaconic acid (IA) is a building block platform chemical which is currently produced industrially from glucose by fermentation with Aspergillus terreus. In order to expand the use of IA, its production cost must be lowered. Softwood has the potential to serve as low cost source of sugars for its production. In this work, 20 A. terreus strains were evaluated for the first time for production of IA from mannose and galactose, sugars derived from softwood. A novel strain was found that gave the highest IA titre reported so far. Galactose was a poor substrate for IA production by A. terreus.

Recent trends in leprosy in a large district of West Bengal, India, revealed by a modified leprosy elimination campaign (MLEC), 1998.

A Modified Leprosy Elimination Campaign (MLEC) in September 1998 in the District of Midnapore, West Bengal, covered a population of 8.1 million people and detected 8181 new cases. Available data from 7328 cases were studied to observe the trend for leprosy in this area. Data are presented on sex and age distribution, classification and the proportions of multibacillary (MB), paucibacillary (PB) and single skin lesion (SSL) cases discovered in a period of only 8 days. The large numbers of people examined in this district and the high total of new cases revealed are in keeping with experience in other parts of the State and in other parts of India. However, many cases were found in endemic areas and these will receive special attention in a second MLEC, planned for January 2000.