32 research outputs found

    Valgus and varus deformity after wide-local excision, brachytherapy and external beam irradiation in two children with lower extremity synovial cell sarcoma: case report

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    BACKGROUND: Limb-salvage is a primary objective in the management of extremity soft-tissue sarcoma in adults and children. Wide-local excision combined with radiation therapy is effective in achieving local tumor control with acceptable morbidity and good functional outcomes for most patients. CASE PRESENTATION: Two cases of deformity after wide-local excision, brachytherapy and external beam irradiation for lower-extremity synovial cell sarcoma are presented and discussed to highlight contributing factors, time course of radiation effects and orthopedic management. In an effort to spare normal tissues from the long-term effects of radiation therapy, more focal irradiation techniques have been applied to patients with musculoskeletal tumors including brachytherapy and conformal radiation therapy. As illustrated in this report, the use of these techniques results in the asymmetric irradiation of growth plates and contributes to the development of valgus or varus deformity and leg-length discrepancies. CONCLUSIONS: Despite good functional outcomes, progressive deformity in both patients required epiphysiodesis more than 3 years after initial management. There is a dearth of information related to the effects of radiation therapy on the musculoskeletal system in children. Because limb-sparing approaches are to be highlighted in the next generation of cooperative group protocols for children with musculoskeletal tumors, documentation of the effects of surgery and radiation therapy will lead to improved decision making in the selection of the best treatment approach and in the follow-up of these patients

    QTL Analysis of Shading Sensitive Related Traits in Maize under Two Shading Treatments

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    During maize development and reproduction, shading stress is an important abiotic factor influencing grain yield. To elucidate the genetic basis of shading stress in maize, an F2:3 population derived from two inbred lines, Zhong72 and 502, was used to evaluate the performance of six traits under shading treatment and full-light treatment at two locations. The results showed that shading treatment significantly decreased plant height and ear height, reduced stem diameter, delayed day-to-tassel (DTT) and day-to-silk (DTS), and increased anthesis-silking interval (ASI). Forty-three different QTLs were identified for the six measured traits under shading and full light treatment at two locations, including seven QTL for plant height, nine QTL for ear height, six QTL for stem diameter, seven QTL for day-to-tassel, six QTL for day-to-silk, and eight QTL for ASI. Interestingly, three QTLs, qPH4, qEH4a, and qDTT1b were detected under full sunlight and shading treatment at two locations simultaneously, these QTL could be used for selecting elite hybrids with high tolerance to shading and high plant density. And the two QTL, qPH10 and qDTS1a, were only detected under shading treatment at two locations, should be quit for selecting insensitive inbred line in maize breeding procedure by using MAS method

    Sum-rule constraints on the surface state conductance of topological insulators.

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    We report the Drude oscillator strength D and the magnitude of the bulk band gap E_{g} of the epitaxially grown, topological insulator (Bi,Sb)_{2}Te_{3}. The magnitude of E_{g}, in conjunction with the model independent f-sum rule, allows us to establish an upper bound for the magnitude of D expected in a typical Dirac-like system composed of linear bands. The experimentally observed D is found to be at or below this theoretical upper bound, demonstrating the effectiveness of alloying in eliminating bulk charge carriers. Moreover, direct comparison of the measured D to magnetoresistance measurements of the same sample supports assignment of the observed low-energy conduction to topological surface states

    Systemic delays in the initiation of antiretroviral therapy during pregnancy do not improve outcomes of HIV-positive mothers: a cohort study

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    <p>Abstract</p> <p>Background</p> <p>Antiretroviral therapy (ART) initiation in eligible HIV-infected pregnant women is an important intervention to promote maternal and child health. Increasing the duration of ART received before delivery plays a major role in preventing vertical HIV transmission, but pregnant women across Africa experience significant delays in starting ART, partly due the perceived need to deliver ART counseling and patient education before ART initiation. We examined whether delaying ART to provide pre-ART counseling was associated with improved outcomes among HIV-infected women in Cape Town, South Africa.</p> <p>Methods</p> <p>We undertook a retrospective cohort study of 490 HIV-infected pregnant women referred to initiate treatment at an urban ART clinic. At this clinic all patients including pregnant women are screened by a clinician and then undergo three sessions of counseling and patient education prior to starting treatment, commonly introducing delays of 2–4 weeks before ART initiation. Data on viral suppression and retention in care after ART initiation were taken from routine clinic records.</p> <p>Results</p> <p>A total of 382 women initiated ART before delivery (78%); ART initiation before delivery was associated with earlier gestational age at presentation to the ART service (p < 0.001). The median delay between screening and ART initiation was 21 days (IQR, 14–29 days). Overall, 84.7%, 79.6% and 75.0% of women who were pregnant at the time of ART initiation were retained in care at 4, 8 and 12 months after ART initiation, respectively. Among those retained, 91% were virally suppressed at each follow-up visit. However the delay from screening to ART initiation was not associated with retention in care and/or viral suppression throughout the first year on ART in unadjusted or adjusted analyses.</p> <p>Conclusions</p> <p>A substantial proportion of eligible pregnant women referred for ART do not begin treatment before delivery in this setting. Among women who do initiate ART, delaying initiation for patient preparation is not associated with improved maternal outcomes. Given the need to maximize the duration of ART before delivery for prevention of mother-to-child HIV transmission, there is an urgent need for new strategies to help expedite ART initiation in eligible pregnant women.</p
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