Site-selective introduction of thiols in unprotected glycosides

Thioglycosides or S-linked-glycosides are important glycomimetics. These thioglycosides are often prepared by glycosylating deoxythio sugar acceptors, which are synthesized via elaborate protecting group manipulations. We discovered that a carbonyl group, formed by site-selective oxidation of unprotected saccharides, can be converted into a thiol moiety. The transformation involves SN1-substitution of a chloro-azo intermediate, formed by oxidation of the corresponding trityl hydrazone, with a thiol. The prepared deoxythio sugars provide, in combination with the recently developed protecting group-free glycosylation of glycosyl fluorides, a protecting group-free synthesis of thioglycosides.</p

Trauma ICU Prevalence Project: the diversity of surgical critical care.

Background:Surgical critical care is crucial to the care of trauma and surgical patients. This study was designed to provide a contemporary assessment of patient types, injuries, and conditions in intensive care units (ICU) caring for trauma patients. Methods:This was a multicenter prevalence study of the American Association for the Surgery of Trauma; data were collected on all patients present in participating centers' trauma ICU (TICU) on November 2, 2017 and April 10, 2018. Results:Forty-nine centers submitted data on 1416 patients. Median age was 58 years (IQR 41-70). Patient types included trauma (n=665, 46.9%), non-trauma surgical (n=536, 37.8%), medical (n=204, 14.4% overall), or unspecified (n=11). Surgical intensivists managed 73.1% of patients. Of ICU-specific diagnoses, 57% were pulmonary related. Multiple high-intensity diagnoses were represented (septic shock, 10.2%; multiple organ failure, 5.58%; adult respiratory distress syndrome, 4.38%). Hemorrhagic shock was seen in 11.6% of trauma patients and 6.55% of all patients. The most common traumatic injuries were rib fractures (41.6%), brain (38.8%), hemothorax/pneumothorax (30.8%), and facial fractures (23.7%). Forty-four percent were on mechanical ventilation, and 17.6% had a tracheostomy. One-third (33%) had an infection, and over half (54.3%) were on antibiotics. Operations were performed in 70.2%, with 23.7% having abdominal surgery. At 30 days, 5.4% were still in the ICU. Median ICU length of stay was 9 days (IQR 4-20). 30-day mortality was 11.2%. Conclusions:Patient acuity in TICUs in the USA is very high, as is the breadth of pathology and the interventions provided. Non-trauma patients constitute a significant proportion of TICU care. Further assessment of the global predictors of outcome is needed to inform the education, research, clinical practice, and staffing of surgical critical care providers. Level of evidence:IV, prospective observational study

William Edwards Ladd, M.D. (1880-1967): the description of his bands.

In the early 20th century, an established surgical specialty catering to pediatric surgery did not exist, and pediatric surgical ailments were operated on by general surgeons. With his devotion to childhood diseases and his unique thinking in surgical development, William E. Ladd would become a leading figure in America by pioneering the field of pediatric surgery

Chlorantraniliprole (Rynaxypyr): A novel DuPont™ insecticide with low toxicity and low risk for honey bees (Apis mellifera) and bumble bees (Bombus terrestris) providing excellent tools for uses in integrated pest management

contribution to session IVTest methodology Background: The effects on bees of chlorantraniliprole (DPX-E2Y45, DuPont™ Rynaxypyr), a new anthranilic diamide insecticide with a novel and very specific mode of action activating insect ryanodine receptors were investigated.Results: Acute toxicity tests with chlorantraniliprole and the formulations, Coragen and Altacor, demonstrated low intrinsic toxicity to honey bees. Low risk for honey bees was demonstrated in semi-field tunnel tests with flowering Phacelia or wheat (with daily sprays of sugar solution to simulate honey dew) at application rates of Coragen of up to 60 g chlorantraniliprole/ha. Low potential of systemic exposure via pollen and nectar of honeybees to chlorantraniliprole was documented in a residue Phacelia tunnel trial with chlorantraniliprole applied to and mixed into bare soil. The impact of Altacor on bumble bees was studied in a greenhouse test in tomato at 40 g chlorantraniliprole/ha. Bumble bees directly over-sprayed during foraging activity with chlorantraniliprole or exposed to treated plants behaved as controls. Conclusion: Chlorantraniliprole formulations provide excellent tools for integrated pest management (IPM) programmes to conserve pollinating honey bees and bumble bees. Keywords: Chlorantraniliprole, Rynaxypyr®, insecticide, side-effects, honey bee, bumble bee, integrated pest management (IPM

Reduced micro-deformation attenuation in large-mode area photonic crystal fibers for visible applications

We consider large-mode area photonic crystal fibers for visible applications where micro-deformation induced attenuation becomes a potential problem when the effective area A_eff is sufficiently large compared to lambda^2. We argue how a slight increase in fiber diameter D can be used in screening the high-frequency components of the micro-deformation spectrum mechanically and we confirm this experimentally for both 15 and 20 micron core fibers. For typical bending-radii (R~16 cm) the operating band-width increases by ~3-400 nm to the low-wavelength side.Comment: Accepted for Optics Letter

Site-Selective Dehydroxy-Chlorination of Secondary Alcohols in Unprotected Glycosides

To circumvent protecting groups, the site-selective modification of unprotected glycosides is intensively studied. We show that site-selective oxidation, followed by treatment of the corresponding trityl hydrazone with tert-butyl hypochlorite and a H atom donor provides an effective way to introduce a chloride substituent in a variety of mono- and disaccharides. The stereoselectivity can be steered, and a new geminal dichlorination reaction is described as well. This strategy challenges existing methods that lead to overchlorination

Venous thromboembolism after penetrating femoral and popliteal artery injuries: an opportunity for increased prevention

Background: Trauma patients with penetrating vascular injuries have a higher rate of venous thromboembolism (VTE). The objective of this study was to determine the risk of VTE formation in penetrating femoral and popliteal vascular injuries and the effects of endovascular management of these injuries. Methods: A retrospective study of Pennsylvania Trauma Outcome Study registry was conducted during a 5-year period (2013-2017). All adult patients with a penetrating mechanism with femoral/popliteal vascular injuries were studied. Primary outcome was incidence of VTE in patients with isolated arterial injuries versus combined arterial/venous injuries. Secondary endpoints were intensive care unit (ICU) length of stay (LOS), hospital LOS and mortality. Statistical comparisons were accomplished using Fisher\u27s exact tests, and parametric two-sample t-tests or non-parametric Wilcoxon rank-sum tests for categorical and continuous variables, respectively. Results: Of the 865 patients with penetrating extremity vascular injuries, 207 had femoral or popliteal artery injuries. Patients with isolated arterial injuries (n=131) had a significantly lower deep venous thrombosis (DVT) rate compared with those with concurrent venous injuries (n=76) (3.1% vs. 13.2%, p=0.008). There were 14 patients in the study who developed DVTs. Among the four patients with isolated femoral or popliteal arterial injuries who had developed DVTs, three had an open repair. Among patients with isolated arterial injuries, those with DVT spend significantly more time on the ventilator (median=2 vs. 0, p=0.0020) compared with patients without DVT. Patients with DVT also had longer stay in the hospital (median=17.5 vs. 8, p=0.0664) and in the ICU (median=3 vs. 1, p=0.0585). Conclusions: Risk of DVT exists in patients with penetrating isolated femoral and popliteal artery trauma. Open repair was associated with significantly higher DVT rates in isolated arterial injuries. Level of evidence: Level IV therapeutic care/management