4,626 research outputs found
Charge density waves and Fermi surface reconstruction in the clean overdoped cuprate superconductor Tl2Ba2CuO6+δ.
Hall effect and quantum oscillation measurements on high temperature cuprate superconductors show that underdoped compositions have small Fermi surface pockets whereas when heavily overdoped, a single much larger pocket is found. The origin of this change in electronic structure has been unclear, but may be related to the high temperature superconductivity. Here we show that the clean overdoped single-layer cuprate Tl2Ba2CuO6+δ (Tl2201) displays CDW order with a remarkably long correlation length ξ ≈ 200 Å which disappears above a hole doping of pCDW ≈ 0.265. We show that the evolution of the electronic properties of Tl2201 as the doping is lowered may be explained by a Fermi surface reconstruction which accompanies the emergence of the CDW below pCDW. Our results demonstrate importance of CDW correlations in understanding the electronic properties of overdoped cuprates
What predicts medical lethality of suicide attempts in Asian youths?
This study explores youth suicide attempts in Singapore using multiple databases of comprehensive archivalrecords. Three years of medical records related to suicide attempters (N = 666) who were admitted to theemergency department of a large teaching hospital in Singapore were subjected to retrospective analysis.Compared to other age groups, a peak in suicide attempts (n = 207) was observed in youths aged between 15and 24 years old (76.3% females; 23.7% males, mean age = 19.30, SD = 2.89). The model using recognized riskand protective factors was significant in predicting medical lethality, and correctly classified 62.8% of highlethality cases. Only resolution of precipitant made a unique statistical significant contribution. Analysis wasseparately conducted for males and females. Implications of the findings are discussed
Mutant p53 cancers reprogram macrophages to tumor supporting macrophages via exosomal miR-1246
TP53 mutants (mutp53) are involved in the pathogenesis of most human cancers. Specific
mutp53 proteins gain oncogenic functions (GOFs) distinct from the tumor suppressor activity
of the wild-type protein. Tumor-associated macrophages (TAMs), a hallmark of solid tumors,
are typically correlated with poor prognosis. Here, we report a non-cell-autonomous
mechanism, whereby human mutp53 cancer cells reprogram macrophages to a tumor supportive and anti-inflammatory state. The colon cancer cells harboring GOF
mutp53 selectively shed miR-1246-enriched exosomes. Uptake of these exosomes by
neighboring macrophages triggers their miR-1246-dependent reprogramming into a cancerpromoting state. Mutp53-reprogammed TAMs favor anti-inflammatory immunosuppression
with increased activity of TGF-β. These findings, associated with poor survival in colon cancer
patients, strongly support a microenvironmental GOF role for mutp53 in actively engaging the
immune system to promote cancer progression and metastasis
Stormiest winter on record for Ireland and UK
Meteorological agencies of Ireland and the UK have confirmed that winter (December to
February) 2013-14 (W2013/14) set records for precipitation totals and the occurrence of
extreme wind speeds1,2,3. Less clear is whether storminess (characterised as the frequency
and intensity of cyclones) during W2013/14 was equally unprecedented. We assess multidecadal
variations in storminess by considering frequency and intensity together and find
that W2013/14 was indeed exceptional. Given the potential societal impacts there is clearly
a need to better understand the processes driving extreme cyclonic activity in the North
Atlantic (NA)
Increased MicroRNA-34b and -34c Predominantly Expressed in Stromal Tissues Is Associated with Poor Prognosis in Human Colon Cancer
published_or_final_versio
Saddle point localization of molecular wavefunctions
The quantum mechanical description of isomerization is based on bound eigenstates of the molecular potential energy surface. For the near-minimum regions there is a textbook-based relationship between the potential and eigenenergies. Here we show how the saddle point region that connects the two minima is encoded in the eigenstates of the model quartic potential and in the energy levels of the [H, C, N] potential energy surface. We model the spacing of the eigenenergies with the energy dependent classical oscillation frequency decreasing to zero at the saddle point. The eigenstates with the smallest spacing are localized at the saddle point. The analysis of the HCN???HNC isomerization states shows that the eigenstates with small energy spacing relative to the effective (v1, v3, l) bending potentials are highly localized in the bending coordinate at the transition state. These spectroscopically detectable states represent a chemical marker of the transition state in the eigenenergy spectrum. The method developed here provides a basis for modeling characteristic patterns in the eigenenergy spectrum of bound states
Primary PEComa of the bladder treated with primary excision and adjuvant interferon-alpha immunotherapy: a case report
BACKGROUND: Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms of uncertain malignant potential, which have in common the co-expression of muscle and melanocytic immunohistochemical markers. CASE PRESENTATION: A 48-year-old man presented with dysuria, passage of urinary sediment and lower abdominal discomfort. A three centimeter mass was identified by cystoscopy in the posterior midline of the bladder. Computerized tomography suggested an enterovesical fistula. The patient underwent laparotomy, partial cystectomy and partial small bowel resection. Pathological examination revealed PEComa of the bladder. The patient underwent adjuvant interferon-α immunotherapy. Subsequent follow-up procedures, including cystoscopy and imaging, have not revealed evidence of recurrence. The patient is clinically free of disease 48 months after surgery. CONCLUSION: This case represents the second documented PEComa of bladder and demonstrates that adjuvant therapies, including anti-angiogenic and immunotherapy, may be considered for patients with locally advanced or metastatic genitourinary PEComa
The effect on survival of continuing chemotherapy to near death
<p>Abstract</p> <p>Background</p> <p>Overuse of anti-cancer therapy is an important quality-of-care issue. An aggressive approach to treatment can have negative effects on quality of life and cost, but its effect on survival is not well-defined.</p> <p>Methods</p> <p>Using the Surveillance, Epidemiology, and End Results-Medicare database, we identified 7,879 Medicare-enrolled patients aged 65 or older who died after having survived at least 3 months after diagnosis of advanced non-small cell lung cancer (NSCLC) between 1991 and 1999. We used Cox proportional hazards regression analysis, propensity scores, and instrumental variable analysis (IVA) to compare survival among patients who never received chemotherapy (n = 4,345), those who received standard chemotherapy but not within two weeks prior to death (n = 3,235), and those who were still receiving chemotherapy within 14 days of death (n = 299). Geographic variation in the application of chemotherapy was used as the instrument for IVA.</p> <p>Results</p> <p>Receipt of chemotherapy was associated with a 2-month improvement in overall survival. However, based on three different statistical approaches, no additional survival benefit was evident from continuing chemotherapy within 14 days of death. Moreover, patients receiving chemotherapy near the end of life were much less likely to enter hospice (81% versus 51% with no chemotherapy and 52% with standard chemotherapy, P < 0.001), or were more likely to be admitted within only 3 days of death.</p> <p>Conclusions</p> <p>Continuing chemotherapy for advanced NSCLC until very near death is associated with a decreased likelihood of receiving hospice care but not prolonged survival. Oncologists should strive to discontinue chemotherapy as death approaches and encourage patients to enroll in hospice for better end-of-life palliative care.</p
A Novel, Orally Delivered Antibody Therapy and Its Potential to Prevent Clostridioides difficile Infection in Pre-clinical Models
Clostridioides difficile infection (CDI) is a toxin-mediated infection in the gut and a major burden on healthcare facilities worldwide. We rationalized that it would be beneficial to design an antibody therapy that is delivered to, and is active at the site of toxin production, rather than neutralizing the circulating and luminal toxins after significant damage of the layers of the intestines has occurred. Here we describe a highly potent therapeutic, OraCAb, with high antibody titers and a formulation that protects the antibodies from digestion/inactivation in the gastrointestinal tract. The potential of OraCAb to prevent CDI in an in vivo hamster model and an in vitro human colon model was assessed. In the hamster model we optimized the ratio of the antibodies against each of the toxins produced by C. difficile (Toxins A and B). The concentration of immunoglobulins that is effective in a hamster model of CDI was determined. A highly significant difference in animal survival for those given an optimized OraCAb formulation versus an untreated control group was observed. This is the first study testing the effect of oral antibodies for treatment of CDI in an in vitro gut model seeded with a human fecal inoculum. Treatment with OraCAb successfully neutralized toxin production and did not interfere with the colonic microbiota in this model. Also, treatment with a combination of vancomycin and OraCAb prevented simulated CDI recurrence, unlike vancomycin therapy alone. These data demonstrate the efficacy of OraCAb formulation for the treatment of CDI in pre-clinical models
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