64 research outputs found
On explosive boiling of a multicomponent Leidenfrost drop
The gasification of multicomponent fuel drops is relevant in various
energy-related technologies. An interesting phenomenon associated with this
process is the self-induced explosion of the drop, producing a multitude of
smaller secondary droplets, which promotes overall fuel atomization and,
consequently, improves the combustion efficiency and reduces emissions of
liquid-fueled engines. Here, we study a unique explosive gasification process
of a tricomponent droplet consisting of water, ethanol, and oil ("ouzo"), by
high-speed monitoring of the entire gasification event taking place in the
well-controlled, levitated Leidenfrost state over a superheated plate. It is
observed that the preferential evaporation of the most volatile component,
ethanol, triggers nucleation of the oil microdroplets/nanodroplets in the
remaining drop, which, consequently, becomes an opaque oil-in-water
microemulsion. The tiny oil droplets subsequently coalesce into a large one,
which, in turn, wraps around the remnant water. Because of the encapsulating
oil layer, the droplet can no longer produce enough vapor for its levitation,
and, thus, falls and contacts the superheated surface. The direct thermal
contact leads to vapor bubble formation inside the drop and consequently drop
explosion in the final stage.Comment: 8 pages, 5 figure
Demonstration of chronometric leveling using transportable optical clocks beyond laser coherence limit
Optical clock network requires the establishment of optical frequency
transmission link between multiple optical clocks, utilizing narrow linewidth
lasers. Despite achieving link noise levels of 10, the final accuracy
is limited by the phase noise of the clock laser. Correlation spectroscopy is
developed to transmit frequency information between two optical clocks
directly, enabling optical clock comparison beyond the phase noise limit of
clock lasers, and significantly enhancing the measurement accuracy or shorten
the measurement time. In this letter, two compact transportable
Ca clocks are employed to accomplish the correlation
spectroscopy comparison, demonstrating an 10 cm level measurement accuracy of
chronometric leveling using a mediocre clock laser with linewidth of 200 Hz.
The relative frequency instability reaches ,
which is about 20 times better than the result with Rabi spectroscopy using the
same clock laser. This research greatly reduces the harsh requirements on the
performance of the clock laser, so that an ordinary stable-laser can also be
employed in the construction of optical clock network, which is essential for
the field applications, especially for the chronometric leveling
Endometrial Cytology as a Method to Improve the Accuracy of Diagnosis of Endometrial Cancer: Case Report and Meta-Analysis
More and more researchers have reported that dilatation and curettage (D&C) or Pipelle had low accuracy, high misdiagnosis, and insufficient rate. Endometrial cytology is often compared with histology and seems to be an efficient method for the diagnosis of endometrial disorders, especially endometrial cancer. We report a case of misdiagnosed endometrial cancer by D&C, but with a positive cytopathological finding. Following that, a meta-analysis including 4,179 patients of endometrial diseases with cyto-histopathological results was performed to assess the value of the endometrial cytological method in endometrial cancer diagnosis. The pooled sensitivity and specificity of the cytological method in detecting endometrial atypical hyperplasia or cancer was 0.91[95% confidence interval (CI) 0.74–0.97] and 0.96 (95% CI 0.90–0.99), respectively. The pooled positive likelihood ratio and negative likelihood ratio was 25.4 (95% CI 8.1–80.1) and 0.10 (95% CI 0.00–0.30), respectively. The diagnostic odds ratio which was usually used to evaluate the diagnostic test performance reached 260 (95% CI 36–1905). So we recommend that D&C and Pipelle are still practical procedures to evaluate the endometrium, cytological examinations should be utilized as an additional endometrial assessment method
Phase diagrams on composition-spread FeTeSe films
FeTeSe, an archetypical iron-based high-temperature
superconductor with a simple structure but rich physical properties, has
attracted lots of attention because the two end compositions, Se content and 1, exhibit antiferromagnetism and nematicity, respectively, making it an
ideal candidate for studying their interactions with superconductivity.
However, what is clearly lacking to date is a complete phase diagram of
FeTeSe as functions of its chemical compositions since phase
separation usually occurs from to 0.9 in bulk crystals. Moreover,
fine control of its composition is experimentally challenging because both Te
and Se are volatile elements. Here we establish a complete phase diagram of
FeTeSe, achieved by high-throughput film synthesis and
characterization techniques. An advanced combinatorial synthesis process
enables us to fabricate an epitaxial composition-spread FeTeSe
film encompassing the entire Se content from 0 to 1 on a single piece of
CaF substrate. The micro-region composition analysis and X-ray diffraction
show a successful continuous tuning of chemical compositions and lattice
parameters, respectively. The micro-scale pattern technique allows the mapping
of electrical transport properties as a function of relative Se content with an
unprecedented resolution of 0.0074. Combining with the spin patterns in
literature, we build a detailed phase diagram that can unify the electronic and
magnetic properties of FeTeSe. Our composition-spread
FeTeSe films, overcoming the challenges of phase separation and
precise control of chemical compositions, provide an ideal platform for
studying the relationship between superconductivity and magnetism.Comment: 13 pages,5 figures and Supplementary Material 3 pages,3 figure
Tissue-specific transcriptomics reveals a central role of CcNST1 in regulating the fruit lignification pattern in Camellia chekiangoleosa, a woody oil-crop
Fruit lignification is of significant economic importance because it affects the quality of fruit and the production of seed oil. The specified lignification pattern in Camellia chekiangoleosa fruits plays critical roles in its seed oil yield, but little is known about how this lignification process is regulated. Here, we report on a comprehensive tissue-specific transcriptomics analysis conducted for C. chekiangoleosa fruit. By mining the differentially expressed genes, we found that lignin biosynthesis and transcriptional regulation pathways were significantly enriched in the lignified tissues. The homolog of NST-like transcription factor, CcNST1, was highly expressed in lignified seed coat and endocarp tissues; transgenic analyses of CcNST1 in Arabidopsis and hybrid poplar revealed the enhanced lignification levels of various tissues. Gene expression analysis of the transgenic lines uncovered potential downstream genes involved in the regulation of lignin biosynthesis. This work provides a valuable gene expression resource and identified the pivotal role of CcNST1 in regulating the lignin biosynthesis underlying fruit lignification
Mutational activation of BRAF confers sensitivity to transforming growth factor beta inhibitors in human cancer cells
Recent data implicate elevated transforming growth factor-β (TGFβ) signalling in BRAF inhibitor drug-resistance mechanisms, but the potential for targeting TGFβ signalling in cases of advanced melanoma has not been investigated. We show that mutant BRAFV600E confers an intrinsic dependence on TGFβ/TGFβ receptor 1 (TGFBR1) signalling for clonogenicity of murine melanocytes. Pharmacological inhibition of the TGFBR1 blocked the clonogenicity of human mutant BRAF melanoma cells through SMAD4-independent inhibition of mitosis, and also inhibited metastasis in xenografted zebrafish. When investigating the therapeutic potential of combining inhibitors of mutant BRAF and TGFBR1, we noted that unexpectedly, low-dose PLX-4720 (a vemurafenib analogue) promoted proliferation of drug-naïve melanoma cells. Pharmacological or pharmacogenetic inhibition of TGFBR1 blocked growth promotion and phosphorylation of SRC, which is frequently associated with vemurafenib-resistance mechanisms. Importantly, vemurafenib-resistant patient derived cells retained sensitivity to TGFBR1 inhibition, suggesting that TGFBR1 could be targeted therapeutically to combat the development of vemurafenib drug-resistance
New Perspectives on Roles of Alpha-Synuclein in Parkinson’s Disease
Parkinson’s disease (PD) is one of the synucleinopathies spectrum of disorders typified by the presence of intraneuronal protein inclusions. It is primarily composed of misfolded and aggregated forms of alpha-synuclein (α-syn), the toxicity of which has been attributed to the transition from an α-helical conformation to a β-sheetrich structure that polymerizes to form toxic oligomers. This could spread and initiate the formation of “LB-like aggregates,” by transcellular mechanisms with seeding and subsequent permissive templating. This hypothesis postulates that α-syn is a prion-like pathological agent and responsible for the progression of Parkinson’s pathology. Moreover, the involvement of the inflammatory response in PD pathogenesis has been reported on the excessive microglial activation and production of pro-inflammatory cytokines. At last, we describe several treatment approaches that target the pathogenic α-syn protein, especially the oligomers, which are currently being tested in advanced animal experiments or are already in clinical trials. However, there are current challenges with therapies that target α-syn, for example, difficulties in identifying varying α-syn conformations within different individuals as well as both the cost and need of long-duration large trials
Cluster-Like Headache Secondary to Anamnesis of Sphenoid Ridge Meningioma: A Case Report and Literature Review
Cluster headache is generally considered to be a primary headache; secondary cluster-like headache is quite rare, while cluster-like headache secondary to meningioma is even rarer. Here, we describe an unusual case with cluster-like headache 2.5 years after sphenoid ridge meningioma surgery. The cluster-like headache and meningioma were on the same side, and even at the same position. Furthermore, the cluster-like headache lasted for 6 months. In addition, the patient did not respond well to conventional treatments for cluster headache, such as oxygen inhalation, carbamazepine, and tramadol. Brain magnetic resonance imaging demonstrated a softening lesion, glial hyperplasia, and localized thickening and enhancement of the dura in the left frontal-temporal lobe. However, positron-emission computed tomography showed reduced metabolism in the left frontal-temporal lobe. Although the possibility of a primary headache cannot be completely eliminated, the association between cluster-like headache and probable tumor recurrence or postoperative changes should be considered
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