A Vehicle Routing Problem with Time Windows and Workload Balancing for COVID-19 Testers: A Case Study.

Due to the COVID-19 pandemic, laboratories have faced unprecedented demand for in-home delivery test services. This drastic demand increase requires a rapid reaction from laboratories to manage their testers in order to respond to the high demand volume and avoid unnecessary costs. This study provides an optimization model based on the vehicle routing problem with time windows by considering the testers' workload balancing to improve laboratories' assignment and routing policies. A medical lab that has faced this situation for its in-home test services is taken as a real-world case in the current study. A mixed-integer programming model is solved for small instances using the CPLEX solver, and an adaptive large neighborhood search algorithm is implemented for large instances. Ultimately, the obtained solutions are compared to the real-world implementation of the lab on a dataset of six consecutive days, and the results are further discussed.

AP1 factor inactivation in the suprabasal epidermis causes increased epidermal hyperproliferation and hyperkeratosis but reduced carcinogen-dependent tumor formation.

Activator protein one (AP1) (jun/fos) factors comprise a family of transcriptional regulators (c-jun, junB, junD, c-fos, FosB, Fra-1 and Fra-2) that are key controllers of epidermal keratinocyte survival and differentiation, and are important drivers of cancer development. Understanding the role of these factors in epidermis is complicated by the fact that each member is expressed in defined cell layers during epidermal differentiation, and because AP1 factors regulate competing processes (that is, proliferation, apoptosis and differentiation). We have proposed that AP1 factors function differently in basal versus suprabasal epidermis. To test this, we inactivated suprabasal AP1 factor function in mouse epidermis by targeted expression of dominant-negative c-jun (TAM67), which inactivates function of all AP1 factors. This produces increased basal keratinocyte proliferation, delayed differentiation and extensive hyperkeratosis. These findings contrast with previous studies showing that basal layer AP1 factor inactivation does not perturb resting epidermis. It is interesting that in spite of extensive keratinocyte hyperproliferation, susceptibility to carcinogen-dependent tumor induction is markedly attenuated. These novel observations strongly suggest that AP1 factors have distinct roles in the basal versus suprabasal epidermis, confirm that AP1 factor function is required for normal terminal differentiation, and suggest that AP1 factors have a different role in normal epidermis versus cancer progression.

Torsion of accessory spleen in an adult patient: imaging findings at CT, MRI and angiography.

A 40-year-old woman presented with acute left upper quadrant pain due to torsion of an accessory spleen around its long vascular pedicle, causing infarction. Torsion of an accessory spleen is extremely rare. As far as we known only 14 cases have previously been reported in the literature, and more than half patients were children. MRI can be helpful in the differential diagnosis of infarction by suggesting haemorrhagic necrosis on the T2-weighted images.

A low cost ECG central station for intensive care.

A electrocardiogram (ECG) central station has been developed for the Intensive Care Unit at Christchurch Hospital. The system allows the selection and display of four ECGs selected from seven bedside monitors in the Unit. It also provides for automatic display, hard copy and audio alarm of ECG from any monitor which has detected an alarm condition--irrespective of whether that channel was being displayed prior to alarm detection. The system comprises a control unit (based on an 8085 microprocessor) and a mobile ECG station (4-channel ECG monitor, ECG recorder and computer terminal). Over the three years since its installation, the central station has been used 24 hours a day by medical and nursing staff and has proven to be a valued and reliable instrument in an intensive care environment.

The status of film/screen mammography. Results of the BENT study.

Results of the Breast Exposure: Nationwide Trends (BENT) study are presented. In this study, data were collected from 42 states and several other jurisdictions and the number of facilities found to have unusually high or low exposures during mammography was determined. Surveyors trained by representatives of the Bureau of Radiological Health then worked with these facilities to determine the source of the problem and recommend corrective measures. Contrast was found to be reduced by high "inherent" filtration, high kVp, or inappropriate imaging conditions, while resolution was impaired by excessive exposure time, as well as inappropriate imaging conditions. These and other problems are discussed and correlated with image quality.