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SUMMARY A series of terranes were accreted to Eurasia in the region of what is now the Tibetan Plateau, including the Qaidam-Qilian, the Songpan-Ganzi, the Qiangtang, the Lhasa and the Tethyan Himalaya terranes. The drift history of the Qiangtang Terrane and the timing of the Lhasa–Qiangtang collision are controversial. To contribute to this topic, here, we palaeomagnetically investigate the Middle-Upper Jurassic limestones of the Yanshiping group in the Zaduo area (32.5°N, 95.2°E), in the Estern Qiangtang Terrane. Twelve sites (133 samples) were processed. A major challenge in palaeomagnetism is the possibility of remagnetization that interferes with palaeogeographic reconstructions. Both thermal and alternating field demagnetizations were carried out to isolate the characteristic remanent magnetization (ChRM). Despite the positive reversals test, rock magnetic information points to a remagnetized ChRM. The ChRM is residing in stable single-domain (SSD) magnetite grains with cogenetic superparamagnetic (SP) particles. The co-occurreance of SSD and SP magnetites generates distinct rock-magnetic properties often refer to as the ‘remagnetized fingerprint’ in limestones. This remagnetization process is also manifested by the widespread occurrence of gypsum veinlets in the limestones. The site-mean direction of the 12 sites after tilt-correction is Ds = 30.6°, Is = 35.6°, κs = 182.9, α95 = 3.2°, corresponding to a palaeolatitude of ∼19.7°± 2.8°N for the study area. The corresponding palaeopole (59.8°N, 202.7°E with A95 = 2.8°) points to an NRM acquired after the India–Eurasia collision. The original sediments were likely anoxic because of the high organic carbon fluxes that prevailed during their deposition. After the India–Eurasia collision, it is envisaged that conditions became more oxic, giving rise to oxidation of iron sulphides to authigenic magnetite and the CRM acquisition. The Zaduo area in the Eastern Qiangtang Terrane has experienced ∼15.7° ± 3.2° (∼1740 ± 350 km) of latitudinal crustal shortening since the Eocene. In addition, the clockwise rotation responding to the India–Eurasia collision is also detected in the Zaduo area.

Robust paleomagnetic results through geological time are one of the keys to understand the drift history of the eastern Qiangtang terrane (EQT). Here, we presented comprehensive petrographic observations and rock magnetic and paleomagnetic analyses of the early Carboniferous Upper Zaduo (ZD) limestone Formation (C1z2) from the Sulucun (SLC) section in the Zaduo area, EQT, to investigate its magnetic originality and geological significance. A total of 12 sites (131 samples) were collected. Photomicrograph observations indicate that the limestone samples were characterized by widespread carbonate veinlets. Electron microprobe and energy dispersive spectrometry analyses confirm that authigenic magnetite formed after pyrite. Rock magnetic analyses reveal the dominant magnetic minerals of pyrite and magnetite, with ‘wasp-waisted’ hysteresis loops and close to the “remagnetization trend” hysteresis parameters. Based on both thermal and alternating field demagnetizations, the characteristic remanent magnetization directions for most samples were isolated: Dg = 6.3°, Ig = 50.1°, kg = 54.9, α95 = 6.2° in-situ, and Ds = 330.2°, Is = 58.9°, ks = 5.9, and α95 = 20.5° after 2-step tilt correction. The κ (α95) value decreases (increases) after tilt-correction, and the ChRM directions failed both the McFadden (1990), Watson and Enkin (1993) fold tests, indicating post-folding magnetizations. The 11 site-mean directions yield a mean in-situ paleopole of 84.4°N, 200.3°E, and A95 = 6.8°, which is coincident with the post ∼53 Myr (especially around 40 Ma) paleopoles of the region. We therefore interpreted that these early Carboniferous limestone samples contain remagnetized magnetizations and that they were obtained after 53 Ma, most likely around 40 Ma, due to the far-field effect of the India–Eurasia collision.

A series of terranes were accreted to Eurasia in the region of what is now the Tibetan Plateau, including the Qaidam-Qilian, the Songpan-Ganzi, the Qiangtang, the Lhasa and the Tethyan Himalaya terranes. The drift history of the Qiangtang Terrane and the timing of the Lhasa–Qiangtang collision are controversial. To contribute to this topic, here, we palaeomagnetically investigate the Middle-Upper Jurassic limestones of the Yanshiping group in the Zaduo area (32.5°N, 95.2°E), in the Estern Qiangtang Terrane. Twelve sites (133 samples) were processed. A major challenge in palaeomagnetism is the possibility of remagnetization that interferes with palaeogeographic reconstructions. Both thermal and alternating field demagnetizations were carried out to isolate the characteristic remanent magnetization (ChRM). Despite the positive reversals test, rock magnetic information points to a remagnetized ChRM. The ChRM is residing in stable single-domain (SSD) magnetite grains with cogenetic superparamagnetic (SP) particles. The co-occurreance of SSD and SP magnetites generates distinct rock-magnetic properties often refer to as the ‘remagnetized fingerprint’ in limestones. This remagnetization process is also manifested by the widespread occurrence of gypsum veinlets in the limestones. The site-mean direction of the 12 sites after tilt-correction is Ds = 30.6°, Is = 35.6°, κs = 182.9, α95 = 3.2°, corresponding to a palaeolatitude of ∼19.7°± 2.8°N for the study area. The corresponding palaeopole (59.8°N, 202.7°E with A95 = 2.8°) points to an NRM acquired after the India–Eurasia collision. The original sediments were likely anoxic because of the high organic carbon fluxes that prevailed during their deposition. After the India–Eurasia collision, it is envisaged that conditions became more oxic, giving rise to oxidation of iron sulphides to authigenic magnetite and the CRM acquisition. The Zaduo area in the Eastern Qiangtang Terrane has experienced ∼15.7° ± 3.2° (∼1740 ± 350 km) of latitudinal crustal shortening since the Eocene. In addition, the clockwise rotation responding to the India–Eurasia collision is also detected in the Zaduo area.

Supplemental material, sj-docx-1-hol-10.1177_09596836221080757 for New insight into pattern divergence of the Indian summer monsoon during the Holocene by Yuwei Zhang, Baiqing Xu, Wanlong Xu and Mei Hou in The Holocene

SummaryWhat is known and objective Postmenopausal osteoporosis is becoming an urgent health problem in China. A once-yearly infusion of zoledronic acid can be very effective for the treatment of postmenopausal osteoporosis in significantly reducing the risk of hip, vertebral and other fractures. This study aimed to investigate zoledronic acid treatment on postmenopausal osteoporosis in Uighur and Han patients in Xinjiang province, China. Methods A self-controlled and prospective trial design was adopted. A total of 155 Uighur and 151 Han patients were enrolled. All subjects received an intravenous infusion of zoledronic acid (5 mg) at day 0 (baseline) and at 12 months. Patients were followed up for 24 months; the bone mineral density (BMD) of the left total hip and L1–L4 vertebrae was measured at day 0 and at 24 months. Results and discussion BMD was significantly higher after zoledronic acid treatment compared with baseline levels in all patients, as assessed at 24 months. Moreover, the BMD of left total hip increased with 2.7% in the Han group was significantly higher than that of the Uighur group with 1.4% (left total hip, 95% CI: 2.6% to 2.8% in Han group vs 1.2% to 1.4% in Uighur group). The BMD of L1–L4 vertebrae increased with 2.2% in the Han group was significantly higher than that of the Uighur group with 1.6% (L1–L4 vertebrae, 95% CI, 2.0% to 2.4% in Han group vs 1.4% to 1.7% in Uighur group); P .05). What is new and conclusion Zoledronic acid appears to be more effective in postmenopausal osteoporosis in Han than in Uighur subjects. The reasons for this require further investigation.

Conventional radiotherapy has a good killing effect on femoral echinococcosis. However, the sciatic nerve around the lesion is irreversibly damaged owing to bystander effects. Although intensity-modulated radiation therapy shows great advantages for precise dose distribution into lesions, it is unknown whether intensity-modulated radiation therapy can perfectly protect the surrounding sciatic nerve on the basis of good killing of femoral echinococcosis foci. Therefore, this study comparatively analyzed differences between intensity-modulated radiation therapy and conventional radiotherapy on the basis of safety to peripheral nerves. Pure-breed Meriones meridiani with bilateral femoral echinococcosis were selected as the research object. Intensity-modulated radiation therapy was used to treat left femoral echinococcosis of Meriones meridianus, while conventional radiotherapy was used to treat right femoral echinococcosis of the same Meriones meridianus. The total radiation dose was 40 Gy. To understand whether intensity-modulated radiation therapy and conventional radiotherapy can kill femoral echinococcosis, trypan blue staining was used to detect pathological changes of bone Echinococcus granulosus and protoscolex death after radiotherapy. Additionally, enzyme histochemical staining was utilized to measure acid phosphatase activity in the protoscolex after radiotherapy. One week after radiotherapy, the overall structure of echinococcosis in bilateral femurs of Meriones meridiani treated by intensity-modulated radiation therapy disappeared. There was no significant difference in the mortality rate of protoscoleces of Echinococcus granulosus between the bilateral femurs of Meriones meridiani. Moreover, there was no significant difference in acid phosphatase activity in the protoscolex of Echinococcus granulosus between bilateral femurs. To understand the injury of sciatic nerve surrounding the foci of femoral echinococcosis caused by intensity-modulated radiation therapy and conventional radiotherapy, the ultrastructure of sciatic nerves after radiotherapy was observed by transmission electron microscopy. Additionally, apoptosis of neurons was examined using a terminal-deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and expression of Bcl-2 and Bax in sciatic nerve tissue was detected by immunohistochemical staining and western blot assay. Our results showed that most neurons in the left sciatic nerve of Meriones meridiani with echinococcosis treated by intensity-modulated radiation therapy had reversible injury, and there was no obvious apoptosis. Compared with conventional radiotherapy, the number of apoptotic cells and Bax expression in sciatic nerve treated by intensity-modulated radiation therapy were significantly decreased, while Bcl-2 expression was significantly increased. Our findings suggest that intensity-modulated radiation therapy has the same therapeutic effect on echinococcosis as conventional radiotherapy, and can reduce apoptosis of the sciatic nerve around foci caused by radiotherapy. Experiments were approved by the Animal Ethics Committee of People's Hospital of Xinjiang Uygur Autonomous Region, China (Approval No. 20130301A41) on March 1, 2013.

During radiotherapy to kill femoral hydatid tapeworms, the sciatic nerve surrounding the focus can be easily damaged by the treatment. Thus, it is very important to evaluate the effects of radiotherapy on the surrounding nervous tissue. In the present study, we used three-dimensional, conformal, intensity-modulated radiation therapy to treat bilateral femoral hydatid disease in Meriones meridiani. The focus of the hydatid disease on the left femur was subjected to radiotherapy (40 Gy) for 14 days, and the right femur received sham irradiation. Hematoxylin-eosin staining, electron microscopy, and terminal deoxynucleotidyl transferase-dUTP nick end labeling assays on the left femurs showed that the left sciatic nerve cell structure was normal, with no obvious apoptosis after radiation. Trypan blue staining demonstrated that the overall protoscolex structure in bone parasitized with Echinococcus granulosus disappeared in the left femur of the animals after treatment. The mortality of the protoscolex was higher in the left side than in the right side. The succinate dehydrogenase activity in the protoscolex in bone parasitized with Echinococcus granulosus was lower in the left femur than in the right femur. These results suggest that three-dimensional conformal intensity-modulated radiation therapy achieves good therapeutic effects on the secondary bone in hydatid disease in Meriones meridiani without damaging the morphology or function of the sciatic nerve.