Leaf size and venation show remarkable diversity across dicotyledons, and are key determinants of plant adaptation in ecosystems past and present. Here we present global scaling relationships of venation traits with leaf size. Across a new database for 485 globally distributed species, larger leaves had major veins of larger diameter, but lower length per leaf area, whereas minor vein traits were independent of leaf size. These scaling relationships allow estimation of intact leaf size from fragments, to improve hindcasting of past climate and biodiversity from fossil remains. The vein scaling relationships can be explained by a uniquely synthetic model for leaf anatomy and development derived from published data for numerous species. Vein scaling relationships can explain the global biogeographical trend for smaller leaves in drier areas, the greater construction cost of larger leaves and the ability of angiosperms to develop larger and more densely vascularised lamina to outcompete earlier-evolved plant lineages.

Background Existing therapies for recurrent or refractory histiocytoses, including Langerhans cell histiocytosis (LCH), juvenile xanthogranuloma (JXG), and Rosai-Dorfman disease (RDD), have limited effectiveness. We report our experience with using clofarabine as therapy in children with recurrent or refractory histiocytic disorders, including LCH (11 patients), systemic JXG (4 patients), and RDD (3 patients). Methods Patients treated with clofarabine for LCH, JXG, or RDD by Texas Children’s Hospital physicians or collaborators between May 2011 and January 2013 were reviewed for response and toxicity. Results Patients were treated with a median of 3 chemotherapeutic regimens prior to clofarabine. Clofarabine was typically administered at 25 mg/m2/day for five days. Cycles were administered every 28 days for a median of six cycles (range: 2–8 cycles). Seventeen of eighteen patients are alive. All surviving patients showed demonstrable improvement after 2–4 cycles of therapy, with eleven (61%) complete responses, four (22%) partial responses, and two patients still receiving therapy. Five patients experienced disease recurrence, but three of these subsequently achieved complete remission. All patients with JXG and RDD had complete or partial response at conclusion of therapy. Side effects included neutropenia in all patients. Recurring but sporadic toxicities included prolonged neutropenia, severe vomiting, and bacterial infections. Conclusion Clofarabine has activity against LCH, JXG, and RDD in heavily pretreated patients, but prospective multi-center trials are warranted to determine long-term efficacy, optimal dosing, and late toxicity of clofarabine in this population.

Uniform, prolonged vascular enhancement, which is desirable for CT angiography and essential for steady-state quantification of blood volume in organs, can be achieved with multiphasic injection.

The analysis demonstrates potential savings and improved quality-of-life associated with the use of ACCESS for patients presenting to rural hospitals with acute ischemic stroke (AIS).

Uniform vascular contrast enhancement and reduced contrast medium volume, which are desirable in CT angiography, can be achieved with exponentially decelerated injection.

Myopia is a global public health issue with a worldwide prevalence of ∼30% and is estimated to rise to 50% by 2050. In addition to the burden associated with routine management of the condition, high myopia predisposes the eye to sight-threatening complications such as myopic maculopathy and glaucoma in adult life. Controlling onset and progression of myopia at a young age can reduce the risk of morbidity associated with high myopia. Progression of myopia can be slowed with various optical, environmental, and pharmaceutical strategies, of which atropine has proven to be the most effective. High-dose atropine (0.5%-1%) is the most effective, but it has significant trade-offs with respect to rebound of myopia on discontinuation and side effects such as photophobia and difficulty with near work (decreased accommodation). Low doses of atropine have been trialed and show a dose-dependent efficacy. However, its mode of action on the ocular tissues leading to slowing eye growth remains unclear and multiple mechanisms and sites in the eye have been postulated to play a role. This review summarizes the role of atropine in controlling myopia and the mechanisms studied to date.

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Decoration of cell membranes with biomolecules, targeting ligands and imaging agents is an emerging strategy to improve functionality of cell-based therapies. Compared to covalent chemistry or genetic expression on the cell surface, lipid painting (i.e., incorporation of lipid-conjugated molecules into the cell bilayer) is a fast, non-damaging and less expensive approach. Previous studies demonstrated excellent incorporation and retention of distearyl indocarbocyanine dye DiI in membranes of cells in vitro and in vivo. In order to exploit the membrane stability of DiI, we synthesized an amino-DiI derivative, to which we subsequently conjugated an antibody (cetuximab), an enzyme (superoxide dismutase), and a small molecule (DyLight 800). Red blood cells have long been used as drug delivery vehicles so they were utilized as a model to study the incorporation of DiI conjugates in the plasma membrane. All the DiI constructs demonstrated fast and efficient ex vivo incorporation in the membrane of mouse RBCs, resulting in millions of exogenous molecules per RBC. Following an intravenous injection into mice, the molecules were detected on circulating RBCs for several days. DiI anchored molecules showed longer residence time in blood and significantly higher area under the curve (AUC) compared to free non-conjugated molecules. Thus, cetuximab, SOD and DyLight painted on RBC showed 5.5-fold, 6.5-fold and 78-fold increase in the AUC, respectively, compared to the non-modified molecules. Lipophilic indocarbocyanine anchors are a promising technology for incorporation of biomolecules and small molecules into biological membranes for in vivo applications.