162 research outputs found

    A Tumor Vascularâ Targeted Interlocking Trimodal Nanosystem That Induces and Exploits Hypoxia

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    Vascularâ targeted photodynamic therapy (VTP) is a recently approved strategy for treating solid tumors. However, the exacerbated hypoxic stress makes tumor eradication challenging with such a single modality approach. Here, a new graphene oxide (GO)â based nanosystem for rationally designed, interlocking trimodal cancer therapy that enables VTP using photosensitizer verteporfin (VP) (1) with codelivery of banoxantrone dihydrochloride (AQ4N) (2), a hypoxiaâ activated prodrug (HAP), and HIFâ 1α siRNA (siHIFâ 1α) (3) is reported. The VTPâ induced aggravated hypoxia is highly favorable for AQ4N activation into AQ4 (a topoisomerase II inhibitor) for chemotherapy. However, the hypoxiaâ induced HIFâ 1α acts as a â hidden brake,â through downregulating CYP450 (the dominant HAPâ activating reductases), to substantially hinder AQ4N activation. siHIFâ 1α is rationally adopted to suppress the HIFâ 1α expression upon hypoxia and further enhance AQ4N activation. This trimodal nanosystem significantly delays the growth of PCâ 3 tumors in vivo compared to the control nanoparticles carrying VP, AQ4N, or siHIFâ 1α alone or their pairwise combinations. This multimodal nanoparticle design presents, the first example exploiting VTP to actively induce hypoxia for enhanced HAP activation. It is also revealed that HAP activation is still insufficient under hypoxia due to the hidden downregulation of the HAPâ activating reductases (CYP450), and this can be well overcome by GO nanoparticleâ mediated siHIFâ 1α intervention.Vascularâ targeted photodynamic therapy (VTP) is integrated with hypoxiaâ activated prodrug (AQ4N) and HIFâ 1α siRNA (siHIFâ 1α) for interlocking trimodal therapy. The VTPâ induced aggravated hypoxia is exploited for efficient AQ4N activation for chemotherapy. HIFâ 1α induced by hypoxia acts as a â hidden brake,â through downregulating CYP450 reductases, to hinder AQ4N activation. siHIFâ 1α is rationally adopted to suppress HIFâ 1α expression upon VTP to enhance AQ4N activation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145505/1/advs661-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145505/2/advs661.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145505/3/advs661_am.pd

    Vitamin C Prevents Hypogonadal Bone Loss

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    Epidemiologic studies correlate low vitamin C intake with bone loss. The genetic deletion of enzymes involved in de novo vitamin C synthesis in mice, likewise, causes severe osteoporosis. However, very few studies have evaluated a protective role of this dietary supplement on the skeleton. Here, we show that the ingestion of vitamin C prevents the low-turnover bone loss following ovariectomy in mice. We show that this prevention in areal bone mineral density and micro-CT parameters results from the stimulation of bone formation, demonstrable in vivo by histomorphometry, bone marker measurements, and quantitative PCR. Notably, the reductions in the bone formation rate, plasma osteocalcin levels, and ex vivo osteoblast gene expression 8 weeks post-ovariectomy are all returned to levels of sham-operated controls. The study establishes vitamin C as a skeletal anabolic agent. Š 2012 Zhu et al

    Pea albumin extracted from pea (Pisum sativum L.) seed protects mice from high fat diet-induced obesity by modulating lipid metabolism and gut microbiota

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    Plant protein has been reported to play a key role in the prevention of obesity and associated complications. It is unknown whether pea albumin may exert anit-obesity and obesity-associated metabolic disorders alleviation. Pea albumin was isolated from pea seed (Pisum sativum L.) and determined its functional role for anti-obesity and metabolic disorders alleviation in high fat diet (HFD)-fed mice. Pea albumin administration reduced body weight gain, improved glucose tolerance and insulin sensitivity, reduced inflammatory cytokines secretion, and alleviated hepatic steatosis in HFD-fed mice. Interestingly, pea albumin inhibited lipid accumulation in 3T3-L1 cells in vitro and modulated lipid metabolism by upregulating critical proteins implicated in lipolysis and fatty acid oxidation, and downregulating lipogenesis in vivo. Moreover, pea albumin restored gut microbial composition to normal fat diet condition and selectively promoted the growth of beneficial gut bacteria (Akkermansia, Parabacteroides etc.). Collectively, the data demonstrated that pea albumin protects mice from HFD-induced obesity and associated metabolic disorders

    Outstanding hydrogen evolution reaction catalyzed by porous nickel diselenide electrocatalysts

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    To relieve our strong reliance on fossil fuels and to reduce greenhouse effects, there is an ever-growing interest in using electrocatalytic water splitting to produce green, renewable, and environment-benign hydrogen fuel via the hydrogen evolution reaction. For commercially feasible water electrolysis, it is imperative to develop electrocatalysts that perform as efficiently as Pt but using only earth-abundant commercial materials. However, the highest performance current catalysts consist of nanostructures made by using complex methods. Here we report a porous nickel diselenide (NiSe_2) catalyst that is superior for water electrolysis, exhibiting much better catalytic performance than most first-row transition metal dichalcogenide-based catalysts, well-studied MoS_2, and WS_2-based catalysts. Indeed NiSe2 performs comparably to the state-of-the-art Pt catalysts. We fabricate NiSe_2 directly from commercial nickel foam by acetic acid-assisted surface roughness engineering. To understand the origin of the high performance, we use first-principles calculations to identify the active sites. This work demonstrates the commercial possibility of hydrogen production via water electrolysis using porous bulk NiSe_2 catalysts

    Efficient hydrogen evolution by ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam

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    With the massive consumption of fossil fuels and its detrimental impact on the environment, methods of generating clean power are urgent. Hydrogen is an ideal carrier for renewable energy; however, hydrogen generation is inefficient because of the lack of robust catalysts that are substantially cheaper than platinum. Therefore, robust and durable earth-abundant and cost-effective catalysts are desirable for hydrogen generation from water splitting via hydrogen evolution reaction. Here we report an active and durable earth-abundant transition metal dichalcogenide-based hybrid catalyst that exhibits high hydrogen evolution activity approaching the state-of-the-art platinum catalysts, and superior to those of most transition metal dichalcogenides (molybdenum sulfide, cobalt diselenide and so on). Our material is fabricated by growing ternary molybdenum sulfoselenide particles on self-standing porous nickel diselenide foam. This advance provides a different pathway to design cheap, efficient and sizable hydrogen-evolving electrode by simultaneously tuning the number of catalytic edge sites, porosity, heteroatom doping and electrical conductivity

    Genetic Background and Clinical Characters of Pediatric Chronic Pancreatitis: Data and Implications from the East

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    Background. The clinical pattern and genetic background of juvenile idiopathic chronic pancreatitis (ICP) are yet unclear. Methods. A retrospective study of 73 Chinese juvenile ICP patients was performed, and genetic tests were carried out to detect relevant mutations using direct sequencing technique and high-resolution melting technique. Subjects without pancreatitis served as controls. Results. The SPINK1 c.194+2T>C variant was present in 56.16% and 42.00% of juvenile and adult ICP patients, respectively (p=0.020), but was not present in any of the control subjects. Thirty-four (46.58%) of the 73 juvenile ICP patients were male, and a significantly higher ratio of male patients in the adult group was identified (46.58% versus 64.00%, p=0.022). Although most of the juvenile patients presented with abdominal pain (70/73, 95.89%), the patterns of pain attack are significantly different in patients with or without SPINK1 c.194+2T>C mutation. Patients carrying the mutation are more likely to present with recurrent acute pancreatitis (70.70%). Conclusions. The main symptom of pediatric ICP was abdominal pain. SPINK1 c.194+2T>C mutation had a higher occurrence in juvenile ICP patients than in adult group and typically presented with recurrent acute pancreatitis. There may be unidentified factors that lead to a greater incidence rate of ICP in adult male population
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