Technical limits of sensitivity for EIT magnetometry.

Optical magnetometers based on electromagnetically induced transparency (EIT) in atomic vapor can in principle achieve outstanding sensitivity and accuracy in a small volume. Up until now, however, the predicted fundamental quantum-noise-limited sensitivity has not been achieved in practice due to various technical limitations associated with the measurement apparatus. Here we analyze these restrictions and propose viable mitigation strategies for performance optimization. As an example, we show that an EIT magnetometer can theoretically achieve sensitivity better than 100 fT at 1 s measurement time under realistic conditions.

[Epidemiology of hip fractures in age groups at high risk for osteoporosis]. / Epidemiologiia perelomov bedra v vozrastnykh gruppakh povyshennogo riska po osteoporozu.

In accordance with the program on osteoporosis epidemiology in subjects over 50, a retrospective study of hip fracture incidence in populations of two Russian towns (Elektrostal and Yaroslavl) was performed. The total population of Elektrostal and Yaroslavl is above 100000 and 600000, respectively. The analysis of medical records of the traumatological departments of the central city hospitals where patients with hip fractures have been admitted and files from outpatient traumatological stations was performed for 1986-1991 and 1982-1991. The towns' administration provided statistical data on relevant population number and age distribution. Hip fracture has been defined as a fracture of the femoral neck or intertrochanteric region fracture (ICD 9 code 820.0 and 820.2). The incidence of hip fracture for the examined period for the town of Elektrostal made up 61/100000 person-years (32 males and 77 females) and for the town of Yaroslavl 61/100000 person-years (45 males and 70 females). Male/female ratio was 1:2 and 1:15, respectively. The occurrence of hip fractures was maximal in subjects over 75 years old. More recent data showed no significant differences in the incidence of hip fractures in the two towns, except a significant rise in hip fracture incidence in female residents of Yaroslavl. Compared to European countries, the incidence of hip fractures in the above towns was significantly lower. The reasons of these differences are unclear and need further investigation.

[A comparative test of Soviet and American diagnostic criteria for osteoarthrosis (gonarthrosis)]. / Sravnitel'noe ispytanie sovetskikh i amerikanskikh diagnosticheskikh kriteriev osteoartroza (gonartroza).

Diagnostic criteria for osteoarthrosis worked out at the Institute of Rheumatology, AMS of the USSR and the criteria for gonarthrosis proposed by the Criteria Committee of American Association of Rheumatology were compared in a clinical trial which involved 76 patients with osteoarthrosis and 29 patients with other rheumatic diseases. The comparative approbation of both criteria has shown their suitability for diagnosing osteoarthrosis of the knee joint and their high sensibility and specificity. It has shown the simplicity and availability of the regression tree method.