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Thyroid schwannoma, a rare neoplasm of the thyroid gland, originates from Schwann cells that form the myelin sheath. A 47-year-old woman presented with a progressively enlarging thyroid nodule, which was monitored by repeated ultrasonography over the previous 2 years. Following a diagnosis of thyroid schwannoma by core needle biopsy and immunohistochemical staining, the patient underwent ultrasoundguided microwave ablation (MWA). Subsequent thyroid ultrasounds indicated a gradual decrease in the tumor's volume, achieving a 12-month volume reduction ratio of 79.20%. No complications were observed. Ultrasound-guided MWA may serve as an effective alternative to conventional surgery for managing thyroid schwannomas. [ABSTRACT FROM AUTHOR]

The Neotethyan subduction and collision with the Asian, Indian, and Australian plates is evidenced by a giant Andean-type arc system and a remarkable Neotethyan igneous belt along the southwestern Eurasian margin. However, the southward extent, and cause, of Neotethyan subduction is poorly understood. Here, a zircon U-Pb dating and whole-rock geochemical study of two groups of Eocene (50–48 Ma) mafic intrusions from Tangse, North Sumatra, helps to unravel the Neotethyan subduction story. Group 1 consists of diabase samples, which have mid-oceanic-ridge– and arc-like geochemical affinities, with low chondrite-normalized La/Yb(cn) (~0.6) ratios and a high measured εNd(t) value of +8.7. Such geochemical signatures indicate that the magmatic rocks were derived from a refractory depleted mantle source that was metasomatized by slab melts. Group 2 consists of gabbro-diorites, which are enriched in the large-ion lithophile elements and depleted in some high field strength elements. These samples have high La/Yb(cn) (2.9–6.6), low Nb/La(cn) (0.2–0.3), εNd(t) values of +1.1 to +5.0, and εHf(t) values of +8.8 to +15.3. Group 2 samples were produced by the melting of a depleted mantle wedge metasomatized by slab fluids. The magmatism provides evidence for the southern continuation of the Neotethyan igneous belt and tectonic system, whereby slab rollback triggered melting and upwelling in an arc–back-arc geodynamic system from South Tibet to SE Asia. [ABSTRACT FROM AUTHOR]

The southeastern (SE) South China Block was mainly influenced by the Paleo-Tethyan and Paleo-Pacific dynamic domains during the Mesozoic. The initial timing of the tectonic transition between these two domains in the SE South China Block still remains debated. The transition would affect the nature of the lithosphere and material provenance of sediments, and, therefore, igneous and sedimentary rocks in the area could record such dynamic processes. In this study, published geochronological and geochemical data of the Triassic and Jurassic igneous rocks and detrital zircon data of contemporaneous sedimentary rocks in the SE South China Block were compiled, aiming to provide constraints on the tectonic transition via tracing the spatial-temporal variations in the nature of the lithosphere and sedimentary provenance signals. The compiled results suggest that the magmatic intensity and volume decreased significantly from the Late Triassic to Early-Middle Jurassic, with an obvious magmatic quiescence between them, and increased from the Early-Middle Jurassic to Late Jurassic. The eNd(t) and zircon eHf(t) values of mafic rocks, granitoids, and shoshonitic rocks remarkably increased from the Late Triassic to Early-Middle Jurassic, indicative of variations in the lithospheric mantle and continental crust. Such variations suggest that the initial tectonic transition occurred at the earliest Early Jurassic. Based on the southward paleocurrents from Early Jurassic sandstone, E-W-trending extension of Early-Middle Jurassic mafic and shoshonitic rocks, and similar sedimentary provenances of Late Triassic and Early-Middle Jurassic sedimentary rocks, these features imply that the SE South China Block was not immediately influenced by the Paleo-Pacific domain during the Early-Middle Jurassic. However, from the Early-Middle Jurassic to Late Jurassic and Early Cretaceous, the spatial distribution, geochemical signatures, magmatic intensity, and magmatic volume of igneous rocks and provenance of sedimentary rocks exhibit obvious variations, and the regional fold hinge direction changed from E-W-trending to NE-trending, suggesting significant effects from Paleo-Pacific subduction on the SE South China Block. Thus, the Mesozoic tectonic transition from the Paleo-Tethyan to the Paleo-Pacific dynamic domain in the SE South China Block likely occurred during the Early-Middle Jurassic. [ABSTRACT FROM AUTHOR]

In Southeast Asia, the Jinshajiang-Ailaoshan suture in Southwest China and the Song Ma zone in Vietnam were generally accepted as the amalgamation boundary of the South China and Simao/Indochina blocks. However, the tectonic location of the Paleotethyan suture in North Laos and its tectonic affinity remain ambiguous. To address this issue, we present the geochemical and geochronological data of a set of mafic and plagiogranitic rocks along the Song Ma suture zone in North Laos. Three groups of rocks with distinctive petrological, geochronological, and geochemical signatures were identified. The ca. 370 Ma Group 1 plagioclase amphibolite was preserved as xenoliths in the ca. 260 Ma granitoids. It exhibits a normal mid-oceanic-ridge basalt (N-MORB)-like, multielemental pattern with highly positive εNd(t) (+3.3 to +10.7) and εHf(t) (+6.68 to +7.41) values and low δ18O values (5.3‰-5.5‰), that are interpreted as products of the Late Devonian - earliest Carboniferous continental rift setting. The ca. 270 Ma Group 2 gabbro/diabase-diorite exhibits arc-like geochemical affinity with the εNd(t), εHf(t), and δ18O values of -5.85 to -3.76, -3.8 to +3.2, and 6.6‰-7.6‰, respectively. It is derived from the metasomatized wedge. The ca. 260 Ma Group 3 plagiogranite shows Nb-Ta and Ti negative anomalies and positive εNd(t) (+3.21 to +4.21), εHf(t) (+8.4 to +13.6), and δ18O (5.9%-6.8%) values, which are indicative of its derivation from mafic oceanic crust in a subduction setting. In combination with the published data, these results support the development of the Carboniferous-Permian Paleotethyan branch in North Laos, which represents the tectonic location of the Song Ma suture zone that spatially connects the Jinshajiang-Ailaoshan suture zone in Southwest China and the Chenxing-Bangxi suture zone in Hainan Island, South China. [ABSTRACT FROM AUTHOR]

In order to verify the early Paleozoic accretionary assemblage in the Indochina interior and constrain the Prototethyan tectonic evolution in Southeast Asia, this study presents a set of new U-Pb geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic data for the fiftytwo representative granitoids in South Laos. The granitoids from the Kontum terrane, Tam Ky-Phuoc Son tectonic zone, and southern Truong Son igneous zone in South Laos yield the crystallization ages of 464-485 Ma, 455-471 Ma, and 427-446 Ma, respectively, with a northerly younging trend within the Indochina interior. They are mainly monzogranite with A/CNK = 0.96-1.99 and K2O > Na2O, which are marked by enrichment in largeion lithophile elements and depletion in high field strength elements with remarkable Nb-Ta, Sr-P, and Ti negative anomalies. Their initial 87Sr/86Sr ratios range from 0.70510 to 0.71559, εNd(t) from -9.5 to -3.0, (206Pb/204Pb)i from 18.65 to 19.72, (207Pb/204Pb)i from 15.66 to 15.80, and (208Pb/204Pb)i from 38.84 to 39.79. The corresponding zircon ɛHf(t) and δ18O values are in the range of -10.6 to +1.0 and 6.88‰ to 8.94‰, respectively. In addition, their Sr-Nd-Pb and Hf-O isotopic compositions are generally similar with those of time-equivalent granitoids in South Tibet and SW Yunnan, China, and synchronous maficintermediate igneous rocks in South Laos, but distinctive from those of the supracrustal sedimentary-derived South China Paleozoic granite and Lincang-Sukhothai S-type granite. The early Paleozoic granitoids in South Laos might have originated from a mixed source of the wedge-derived juvenile crust coupled with supracrustal materials. All these data synthetically suggest the southward subduction of the Tam Ky-Phuoc Son Ocean and the northerly on-growing Ordo-Silurian accretionary orogenesis within the previously defined "single-ancient" Indochina block. The assemblage of the Indochina block might initiate at ca. 430 Ma in the Silurian and terminate in the Early-Middle Devonian. [ABSTRACT FROM AUTHOR]

To better reveal the tectonic process of the Jiangnan Orogen in creating the united South China Block (SCB), a set of new geochronological, geochemical, and Sr-Nd-Hf-O isotopic data is herein presented for the coeval early Neoproterozoic mafic to acid rocks in the Lengjiaxi Group and its equivalents. Our data show that these rocks belong to subalkaline basalt, basaltic andesite, andesite, and dacite in composition, and can be geochemically classified into N-MORB- and arc-like mafic (Group 1 and Group 2, respectively), along with high-Mg andesiticdacitic (Group 3) rocks. They yield zircon U-Pb ages of 837 ± 4 Ma, 832 ± 11 Ma, and 835 ± 7 Ma, respectively, suggesting their early Neoproterozoic (ca. 835 Ma) origin. Group 1 has SiO2 = 47.21-52.45 wt%, MgO = 7.36-10.07 wt% with Mg-number of 56-68, 87Sr/86Sr(t) = 0.7062-0.7136 and εNd(t) = +1.3-+9.4, along with N-MORBlike REE-(rare earth element) and PM (primitive mantle)-normalized patterns, suggesting its derivation from a refractory MORB-like source newly introduced by slab-derived fluid. The Group 2 samples are classified as tholeiitic basalt and basaltic andesite with SiO2 = 48.78-55.75 wt%, MgO = 7.70-12.74 wt%, Mg-number = 63-77, 87Sr/86Sr(t) = 0.7046-0.7098 and εNd(t) = -1.6 to -0.4. They exhibit similar "spiky" REE- and PM-normalized patterns to typical arc basalt, with pronounced enrichment in (large ion lithophile elements) and sharp depletion in (high field strength elements), probably inheriting from a sub-arc source modified by fluids and/or melts released from recycled sedimentary component. The Group 3 rocks show SiO2 = 57.74-66.30 wt%, FeOt = 6.22--8.59 wt%, Mg-number = 43-66, K2O+Na2O = 3.18-6.17 wt% with K2O/Na2O of 0.59-3.28, classified as high-Mg andesites and dacites. Diagnostic elemental and isotopic ratios of Group 3 include (La/Yb)cn = 7.7-11.4, (Gd/Yb)cn = 1.44-1.87, Eu/Eu* = 0.49--0.80, Nb/La = 0.27-0.42 and εNd(t) = -7.3 to -5.4, resembling to those of other early Neoproterozoic high-Mg intermediate rocks in the SCB, originating from a mantle wedge source with proportional addition of the recycled SCB sediment-derived components. In combination with the available data and geological observations, it is concluded that the N-MORB- and arc-like mafic, along with high-Mg andesitic rocks are coeval in the Lengjiaxi Group and its equivalents along the central Jiangnan Orogen and formed at ca. 847-832 Ma of the early Neoproterozoic period. The synthesis of these observations suggests the development of an early Neoproterozoic continental arc-basin setting. The arc-basin system westerly subducted and finally closed at ca. 830 Ma and the assembly of the Yangtze and Cathaysia blocks terminated at ca. 810 Ma along the central Jiangnan Orogen. [ABSTRACT FROM AUTHOR]

The existence of Himalayan long-eared bats, Plecotus homochrous (Chiroptera, Vespertilionidae), in China has not been previously confirmed. In this study, four bats captured with harp traps from two sites in the Maoershan National Nature Reserve in Guangxi, China were investigated. These bats have long, wide auricles, each with a prominent tragus. The length of each auricle is about the same as that of a forearm. Hairs on the ventral fur have a dark base with mixed grey and yellowish tips; those on the dorsal fur also have a dark base and are bicolored with brown tips. The thumbs are very short. A concavity is present in the front of the dorsal side of the cranium. Based on morphological characteristics and phylogeny using Cyt b gene sequences, these bats were identified as P. homochrous, thus confirming the existence of Himalayan long-eared bats in China. [ABSTRACT FROM AUTHOR]

In this paper we give some characterizations for idempotent-separating congruences on E-inversive semigroups whose idempotents form a rectangular band. We also give some characterizations for this kind of congruences on E*-dense semigroups whose idempotents form a *-rectangular band, which are analogous to parts for E-inversive semigroups. [ABSTRACT FROM AUTHOR]

A numerical method is used to solve the integro-differential generalized telegraphists’ equations for the total (single and multiple) diffusely scattered radiation wave amplitudes. These equations were derived using a full wave approach. The singularities of the scattering coefficients are removed on integrating by parts. A stationary phase approximation is used to obtain the far fields. The numerical solutions are obtained for one-dimensional deterministic surfaces. The numerical results for the total (single and multiple) diffusely scattered fields are in good agreement with the earlier single scatter analytical results when the maximum surface slope is less than 30 degrees. The earlier single scatter analytical solutions are based on the assumption that the total field impressed upon a rough surface is associated with the incident field only. This assumption is not made for the evaluation of the numerical results presented here. The earlier analytical results are in total agreement with the small perturbation results when the rough surface height and slopes are of the same order of smallness. © 1997 by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Youjiang Basin is usually regarded as an important foreland basin in the southern part of the South China Block that is related to the convergence of the South China and Indochina blocks during the Permian-Triassic. However, the nature of the basin remains controversial due to questions about the subduction polarity and suture boundary between these two blocks. Permian-Triassic felsic volcanics across the Dian-Qiong and Song Ma suture zones could offer new insights into the convergent processes of the South China and Indochina blocks. This study presents detailed petrological, zircon U-Pb dating, and Hf-O isotope and whole-rock geochemical analyses for the Triassic felsic volcanics of the Youjiang Basin (northeast of the Dian-Qiong). The dacites and rhyolites from the Beisi and Baifeng Formations were dated at ca. 240-245 Ma. All of the felsic volcanics are characterized by high SiO2 (69.40-73.15 wt%), FeOt/MgO, 10000*Ga/Al, and TZr, δ18O (9.7-11.8‰) and negative εNd(t) (from -9.6 to -12.3) and zircon εHf(t) (from -6.2 to -14.5) with A-type granitoid geochemical affinities, suggesting the reworking of crustal rocks in an extensional setting. Permian-Triassic felsic igneous rocks display similar geochemical signatures across the Dian-Qiong suture zone, whereas they show distinctive Sr-Nd and zircon Hf-O isotopes across the Song Ma suture zone. The felsic igneous rocks to the northeast of the Song Ma suture zone have much lower εNd(t) and higher δ18O with negative zircon εHf(t) than those to the southwest, which have positive zircon εHf(t). Combined with other geological and geophysical features, it is inferred that the Song Ma suture zone was probably the suture boundary between the South China and Indochina blocks, and the Youjiang Basin was likely a peripheral foreland basin in response to the southwestward convergence of the South China Block toward the Indochina Block. [ABSTRACT FROM AUTHOR]

Mean annual air temperature (MAAT) and precipitation isotope records for the Holocene were obtained from the analysis of the relative distribution of branched glycerol dialkyl glycerol tetraethers and compound-specific hydrogen isotope ratios of leaf waxes from a sediment core from Aweng Co on the western Tibetan Plateau (WTP). Our results indicate that the Indian monsoon mainly influenced Aweng Co during the Holocene. During the early Holocene, when summer insolation was at a maximum, the monsoonal influence was strong and the climate was warm and wet. Both the summer and winter insolation were relatively weak, and Aweng Co was cool and dry during the middle Holocene (6-3 ka), indicating a weakening of the Indian monsoon. The southward displacement of the Intertropical Convergence Zone and relatively low atmospheric methane content may have contributed to the middle Holocene cooling on the WTP. During the late Holocene, with a further increase in winter insolation and decrease in summer insolation, the summer monsoon weakened and the MAAT on the WTP gradually increased. Depleted leaf wax hydrogen isotope ratios during the late Holocene can be attributed to accelerated glacier melting because of the elevated MAAT. [ABSTRACT FROM AUTHOR]

The Lincang-Inthanon tectonic belt is a major tectonic boundary within the south-eastern Tibetan Plateau and Indo-China Peninsula, which are typical examples of tectonic extrusion in SE Asia. The Lincang strain zone, Lancang-Gengma fault, and Inthanon metamorphic complex make up this nearly N--S-striking tectonic belt, which separates the Baoshan--Shan Thai and Simao-Indochina terranes. New petrographic, structural, and mica 40Ar/39Ar geochronological studies were conducted to reveal their deformation styles and constrain the timing of their tectonic evolution. W--E-directed compression related to the subduction of the Paleotethyan Ocean with subsequent continental collision and sinistral ductile shearing in the early Oligocene are recorded along the Lincang strain zone. The Lancang-Gengma fault zone switched from sinistral shearing to dextral motion in the late Cenozoic and shows a deformation history similar to that of the parallel Red River fault. The Inthanon metamorphic complex may have experienced crustal shortening in the early Cenozoic, followed by sinistral transtension in the early Miocene. The Lincang-Inthanon tectonic belt shows many lithological, tectonic evolutionary, and metamorphic similarities with the Gaoligong, Chongshan, and Ailaoshan--Red River shear zones. Therefore, the sinistral shearing along the Lincang-Inthanon tectonic belt and the Chongshan shear zone in the north, which may have initiated since the early Oligocene, played an important role in adjusting differential extrusion and rotation of the Baoshan--Shan Thai and SimaoIndochina terranes. Our results delineate the regional tectonic framework and provide insights into the characteristics and geodynamics of intracontinental deformation in the eastern India-Eurasia oblique convergence zone. [ABSTRACT FROM AUTHOR]

Background-Upregulated by atheroprotective flow, the transcription factor Krüppel-like factor 2 (KLF2) is crucial for maintaining endothelial function. MicroRNAs (miRNAs) are noncoding small RNAs that regulate gene expression at the posttranscriptional level. We examined the role of miRNAs, particularly miR-92a, in the atheroprotective flow-regulated KLF2. Methods and Results-Dicer knockdown increased the level of KLF2 mRNA in human umbilical vein endothelial cells, suggesting that KLF2 is regulated by miRNA. In silico analysis predicted that miR-92a could bind to the 3' untranslated region of KLF2 mRNA. Overexpression of miR-92a decreased the expression of KLF2 and the KLF2-regulated endothelial nitric oxide synthase and thrombomodulin at mRNA and protein levels. A complementary finding is that miR-92a inhibitor increased the mRNA and protein expression of KLF2, endothelial nitric oxide synthase, and thrombomodulin. Subsequent studies revealed that atheroprotective laminar flow downregulated the level of miR-92a precursor to induce KLF2, and the level of this flow-induced KLF2 was reduced by miR-92a precursor. Furthermore, miR-92a level was lower in human umbilical vein endothelial cells exposed to the atheroprotective pulsatile shear flow than under atheroprone oscillatory shear flow. Anti-Ago1/2 immunoprecipitation coupled with real-time polymerase chain reaction revealed that pulsatile shear flow decreased the functional targeting of miR-92a precursor/KLF2 mRNA in human umbilical vein endothelial cells. Consistent with these findings, mouse carotid arteries receiving miR-92a precursor exhibited impaired vasodilatory response to flow. Conclusions-Atheroprotective flow patterns decrease the level of miR-92a, which in turn increases KLF2 expression to maintain endothelial homeostasis. [ABSTRACT FROM AUTHOR]

The transcription factor Krüppel-like factor 2 (KLF2) is required for the quiescent and migratory properties of naive T cells. Statins, a class of HMG-CoA reductase inhibitors, display pleiotropic immunomodulatory effects that are independent of their lipid-lowering capacity and may be beneficial as therapeutic agents for T cell-mediated inflammatory diseases. Statins upregulate KLF2 expression in endothelial cells, and this activity is associated with an antiinflammatory phenotype. We therefore hypothesized that the immunomodulatory effects of statins are due, in part, to their direct effects on T cell KLF2 gene expression. Here we report that lipophilic statin treatment of mouse and human T cells increased expression of KLF2 through a HMG-CoA/prenylation-dependent pathway. Statins also diminished T cell proliferation and IFN-gamma expression. shRNA blockade of KLF2 expression in human T cells increased IFN-gamma expression and prevented statin-induced IFN-gamma reduction. In a mouse model of myocarditis induced by heart antigen-specific CD8+ T cells, both statin treatment of the T cells and retrovirally mediated overexpression of KLF2 in the T cells had similar ameliorating effects on disease induction. We conclude that statins reduce inflammatory functions and pathogenic activity of T cells through KLF2-dependent mechanisms, and this pathway may be a potential therapeutic target for cardiovascular diseases. [ABSTRACT FROM AUTHOR]