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OBJECTIVE: Musculoskeletal pain is the most prominent clinical manifestation of more than 150 musculoskeletal disease conditions, and its effective long-term management poses a great challenge to healthcare systems globally. For this, it is important to understand current research progress on musculoskeletal pain management. The purpose of the present study is to provide a comprehensive insight into the current state of research and global trends in musculoskeletal pain management. METHODS: Publications on musculoskeletal pain management from 1972 to 2021 were retrieved from the Science Citation Index-Expanded (SCIE) database. Included articles were any article type related to aspects of musculoskeletal pain management, including etiology, mechanisms, epidemiology, treatment, outcomes, side effects, and patient compliance. Publication data were analyzed using bibliometric methods. The software VOSviewer was employed to perform bibliographic coupling, co-authorship, co-citation, and co-occurrence analysis, and to visualize publication tendencies in musculoskeletal pain management. RESULTS: A total of 5475 articles were included in this study. The number of global publications on musculoskeletal pain management has escalated annually. Based on the number of publications and citations from the published literature, as well as the H-index, the United States led global contributions in this area. The institutions making the highest contributions were the League of European Research Universities (LERU), the University of Sydney, and Harvard University. The journal BMC Musculoskeletal Disorders published the highest number of articles in this area. The published studies fall under six groups: "Prevention and rehabilitation," "Etiology and diagnosis," "Clinical study," "Epidemiology," "Mental health," and "Education." High-quality primary studies and epidemiology are predicted to be the next prevailing topics in this field of research. CONCLUSIONS: Based on current global trends, the number of publications on musculoskeletal pain management will continue to increase. Future studies will likely place more emphasis on high-quality randomized controlled trials (RCTs) and epidemiological studies.

Background The number of revision Total Knee Arthroplasty (TKA) is rising in many countries. This study aimed to assess causes for revision TKA in China and compared reasons with previously published data. Methods In this study patients who had revision TKA between 2007 and 2020 were retrospectively included. Revision causes were categorized using all available information from patients’ records including preoperative diagnostics, intraoperative findings as well as the periprosthetic tissue analysis’ results. Patients were divided into early (up to 2 years) and late revision (more than 2 years). The reason for revision before 2012 and after 2012 was also compared. Results We assessed 337 patients who underwent 373 revision TKAs. In 345 knees this was the first revision surgery after primary TKA. Among the first revisions, half of the revisions were late revisions (50.4%). Overall, the most frequent reason for the revision was infection (38.6%), followed by aseptic loosening (28.1%) and instability (10.1%). Infection (56.1%) and aseptic loosening (49.4%) were the most frequent reason for early and late revisions. Conclusions In our specialized arthroplasty center infection was the most common reason for revision. Infection and aseptic loosening needed to be considered for early or late-stage revision.

BackgroundThis study aimed to determine whether the accelerometer-based navigation (ABN) could improve the accuracy of restoring mechanical axis (MA), component positioning, and clinical outcomes compared to conventional (CON) total knee arthroplasty (TKA).MethodsA total of 301 consecutive patients (ABN: 27, CON: 274) were included. A 1:4 propensity score matching (PSM) was performed between the two groups according to preoperative demographic and clinical parameters. The postoperative MA, femoral coronal angle (FCA), femoral sagittal angle (FSA), tibial coronal angle (TCA) and tibial sagittal angle (TSA) were compared. Absolute deviations of aforementioned angles were calculated as the absolute value of difference between the exact and ideal value and defined as norms if within 3°, otherwise regarded as outliers. Additional clinical parameters, including the Knee Society knee and function scores (KSKS and KSFS) and range of motion (ROM), were assessed at final follow-up (FU) (mean FU was 21.88 and 21.56 months respectively for ABN and CON group). A secondary subgroup analysis and comparison on clinical outcomes were conducted between norms and outliers in different radiological parameters.ResultsA total of 98 patients/102 knees were analyzed after the PSM (ABN: 21 patients/24 knees, CON: 77 patients/78 knees). In the ABN group, the mean MA, FCA and TSA were significantly improved (p = 0.019, 0.006, p = 0.003, 0.021, 0.042, 0.013, respectively for MA, FCA, FSA, and TSA). The absolute deviations of FSA and TSA were also significantly lower in the ABN group (p = 0.020, 0.048, respectively). No significant differences were found in either mean value, absolute deviation or outlier ratio of TCA between two groups. On clinical outcomes, there were no significant differences between two groups, although KSKS, KSFS and ROM (p ConclusionsThe ABN could improve the accuracy and precision of mechanical alignment and component positioning without significant improvement of clinical outcomes. Further high quality studies with long term FU are warranted to comprehensively evaluate the value of the ABN.

Total knee arthroplasty (TKA) for patients with valgus deformity (> 10 degrees) is technically challenging and has produced variable clinical results in terms of deformity correction, instability, and overall outcomes. The lateral parapatellar approach (LPA) is an alternative to the traditional medial parapatellar approach with potential advantages of direct access for release of tight lateral ligamentous structures with preservation of the medial structures, optimized patellar tracking, preserved medial blood supply to the patella, and less use of constrained implants. We present a case series of a single institution's experience with use of a modified LPA using a Z-capsuloplasty for 35 primary TKA cases in 30 patients with osteoarthritis and Ranawat's type-II fixed valgus deformity with attenuation of medial soft tissues. The mean age of patients was 64.8 years (range: 42–78 years). Follow-up duration was a mean of 47.3 months (range: 3–130 months). The patients were assessed pre- and postoperatively using radiographic measurement of the anatomic femorotibial angle (FTA) and clinical measurement of range of motion (ROM) and the Chinese knee society score (KSS). Complications and reoperations were recorded. The mean coronal alignment was corrected from 20.4 degrees of valgus (range: 11.3–42 degrees) preoperatively to 7.0 degrees of valgus (range: 3.6–15.1 degrees) postoperatively. One case required use of a constrained condylar design implant. At a mean of 47.3 months, the mean Knee Society objective and functional scores improved to 91.8 ± 6.6 and 84.3 ± 18.2 points, respectively. Mean ROM was 94.9 degrees preoperatively and 105.7 degrees postoperatively. Three cases (8.6%) had postoperative complications, including transient common peroneal nerve palsy, hematoma, and deep infection. One patient underwent two-stage revision for infection. There were no cases of late instability. The modified LPA using a Z-capsuloplasty is a reproducible and effective surgical technique for performing TKA in the setting of osteoarthritis and severe valgus deformity.

We sought is to determine the mechanism of failure among primary total knee arthroplasties (TKAs) performed at a single high-volume institution by asking the following research questions: (1) What are the most common failure modes for modern TKA designs? and (2) What are the preoperative risk factors for failure following primary TKA?From May 2007 to December 2012, 18,065 primary TKAs performed on 16,083 patients at a single institution were recorded in a prospective total joint arthroplasty registry with a minimum of 5-year follow-up. We retrospectively reviewed patient charts to determine a cause of failure for primary TKAs. A cox proportional hazard model was used to determine the risk of revision surgery following primary TKA.The most common reasons for failure within 2 years after TKA were infection and stiffness. The multivariable regression identified the following preoperative risk factors for TKA failure: history of drug abuse (hazard ratio [HR] 4.68; P = 0.03), deformity/mechanical preoperative diagnosis (HR 3.52; P.01), having a constrained condylar knee implant over posterior-stabilized implant (HR 1.99; P.01), post-traumatic/trauma preoperative diagnosis (HR 1.78; P = .03), and younger age (HR 0.61; P.01) CONCLUSION: These findings add to the growing data that primary TKAs are no longer failing from polyethylene wear-related issues. This study identified preoperative risk factors for failure of primary TKAs, which may be useful information for developing strategies to improve outcomes following TKA.

Implant malalignment in primary TKA has been reported to increase stresses placed on the bearing surfaces of implant components. We used a longitudinally maintained registry coupled with an implant retrieval program to consider whether preoperative, postoperative, or prerevision malalignment was associated with increased risk of revision surgery after TKA. (1) What is the relative polyethylene damage on medial and lateral compartments of the tibial plateaus from revised TKAs? (2) Does coronal TKA alignment affect implant performance, such that TKAs aligned in varus are predisposed to experience increased polyethylene damage? (3) Does TKA alignment differ between postoperative and prerevision radiographs, and if so, what does this difference suggest about the mechanical contact load placed on a knee with a TKA? Between 2007 and 2012, we performed 18,065 primary TKAs at our institution. By March 2016, 178 of those TKAs (1%) were revised at our center at least 2 years after primary surgery at our institution. Eighteen of those TKAs were excluded from this analysis because the tibial insert was not explanted during revision surgery, and four more were excluded because the inserts were lost or returned to the patient before the study was initiated, leaving 156 retrieved polyethylene tibial inserts (in 153 patients) revised at greater than 2 years after the primary TKA for this retrospective study. Patients who underwent revision surgery elsewhere were not considered here, since this study depended on having retrieved components. Polyethylene damage modes of burnishing, pitting, scratching, delamination, surface deformation, abrasion, and third-body debris were subjectively graded on a scale of 0 to 3 to reflect the extent and severity of each damage mode. On preoperative, postoperative, and prerevision radiographs, overall alignment, femoral alignment, and tibial alignment in the coronal plane were measured according to the protocol recommended by the Knee Society. Knees with more overall varus alignment after TKA had increased total damage on the retrieved tibial inserts (Spearman’s rank correlation coefficients of −0.3 [95% CI, −0.4 to −0.1; p = 0.001]). We also found revised TKAs tended to drift back into greater varus before revision surgery, with a mean (SD) of 3.6° ± 4.0° valgus for postoperative alignment compared with 1.7° ± 6.4° prerevision (p = 0.04). Despite surgical efforts to achieve neutral mechanical alignment, remaining varus alignment places an increased contact load on the polyethylene articular surfaces. The drift toward further varus alignment postoperatively is consistent with the knee adduction moment remaining high after surgery. While we found a predisposition toward recurrence of the preoperative varus deformity, we did not find increased medial as opposed to lateral polyethylene damage, which may be explained by the curve-on-curve toroidal design of the articulating surfaces of the TKA implants in this study.

Tourniquets are still widely used in total knee arthroplasty (TKA), although they may be associated with several adverse effects. An observer-blinded, randomized, controlled trial was performed to evaluate the effects of tourniquet use in TKA. Fifty participants who underwent staged bilateral TKA were recruited for this study. The first-side TKA was randomly allocated to either long-duration tourniquet use or short-duration tourniquet use followed by a 3-month washout period and crossover to the other tourniquet strategy for the opposite-side TKA. Blood loss was monitored perioperatively. The operating time, allogeneic blood transfusion rate, thigh pain, knee pain, limb swelling, clinical outcome as measured by the Likert-type Western Ontario and McMaster University (WOMAC) score, straight leg raising and knee active range of motion (ROM) were also recorded. The long-duration tourniquet group exhibited reduced total blood loss [−99.1 ml, 95 % confidence interval (CI) −168.1 to −30.1, P = 0.0411] and intraoperative blood loss (−225.2 ml, 95 % CI −369.5 to −80.9, P = 0.0071) compared with the short-duration tourniquet group. However, there were greater postoperative blood loss (69.6 ml, 95 % CI 21.1 to 118.2, P = 0.0282) and hidden blood loss (52.8 ml, 95 % CI 10.5 to 95.1, P = 0.0332) in the long-duration tourniquet group. The short-duration tourniquet group showed better outcomes for thigh and knee pain, limb swelling, WOMAC score at 6-week follow-up, straight leg raising and knee ROM. Similar allogeneic blood transfusion rates were observed for both groups. Total and intraoperative blood losses were reduced with the long-duration tourniquet use, whereas the short-duration tourniquet use would reduce postoperative and hidden blood losses without increasing the allogeneic blood transfusion rate. In addition, short-duration tourniquet use would result in faster recovery and less pain during the early rehabilitation period following TKA. I.

Necrotizing enterocolitis (NEC) is a life-threatening condition that can occur in about 7% of pre-term infants, and approximately 20% to 30% of the cases will end in death. An overactive immune response is thought to be a primary instigator of many symptoms during NEC. Hence, we hypothesized that NEC patients might present impairment in regulatory T (Treg) cells that limited their capacity to contain the excessive inflammation-induced damage. To investigate this, peripheral blood mononuclear cells were collected from NEC and non-NEC infants with matching age and weight. Treg cells, identified as CD3+CD4+CD25+/hiFoxp3+ T cells, were present at significantly lower frequency in NEC infants than in non-NEC infants. We also observed that the frequency of IL‑17+ CD4+ T cells was significantly higher in NEC infants, while the frequencies of IL‑10+ and TGF‑β+ CD4+ T cells were significantly lower in NEC infants. The CD4+CD25+/hi Treg cells from NEC infants were capable of suppressing CD4+CD25− T conventional cell proliferation, but with significantly reduced potency than the CD4+CD25+/hi Treg cells from non-NEC infants. In addition, the CD4+CD25+/hi Treg cells from non-NEC infants, but not those from NEC infants, were capable of suppressing IL‑17 expression. Furthermore, the CD4+CD25+/hi Treg cells from NEC infants displayed reduced expression of CTLA‑4, LAG‑3, and Helios, compared to those from non-NEC infants. Overall, these results demonstrated that Treg cells from NEC infants displayed a multitude of functional impairments, and suggested that Treg cells might serve as a treatment target in NEC.

Necrotizing enterocolitis (NEC) is a potentially fatal disease that develops in the intestinal tract of newborn infants. An overactive immune system in the intestinal tract of NEC patients not only propagates inflammation and mediates tissue damage, but may also radiate the disease systemically and impose injury to distant organs. We previously identified impairment in the Treg compartment in NEC patients. Here, we hypothesized that monocytes, which could promote iTreg differentiation both in vitro and in vivo , were dysregulated in NEC infants. In age-, sex-, and weight-matched NEC infants and healthy control infants, the monocytes from PBMCs were investigated. Monocytes from NEC infants presented significantly higher TLR4 expression. With or without LPS stimulation, monocytes from NEC infants presented elevated TNF-α and IL-6 expression, together with reduced expression of TGF-β. When incubated with autologous CD4 + T cells, monocytes from NEC infants preferentially promoted the differentiation of RORγt-expressing Th17 cells, but not Foxp3-expressing Treg cells. However, using exogenous TGF-β and IL-10, the development of Foxp3 expression could be significantly elevated. Together, these results demonstrate that monocytes in NEC patients displayed a proinflammatory profile that might contribute to the production of proinflammatory cytokines and the suppression of Treg cells.

In this paper, aiming at the problem of bearing mechanism in granular material , we make a study about effect of granular shape on the force chain structure and the bearing capacity by physical experiment and numerical simulation. The effects of the particle shape on boundary constraint force, geometric configuration of force chain and evolution of the local shear zone in the loading process are analyzed. During loading process, compared with the boundary constraint force of the circular particles, the fluctuation of the boundary constraint force of the elliptical granular system with different friction coefficient is significant and the geometrical construction of the force chain in the granular system reconstruct frequently. Furthermore we have studied the effect of cyclic shear loading on the bearing properties of the particles. Results of this study provide a theoretical basis for the effect of the particle’s shape on the microscopic structure and the bearing capacity in the granular system.

In this paper, aiming at the problem of bearing mechanism in granular material, we design a granular material photoelastic device with multi-way loading to study the micro mechanical structure of the granular system. In this device, we not only design a vertical compression and horizontal shear system, but also develop an automatic data acquisition system to collect boundary force data and photoelastical image during the loading process. The grating ruler is used to collect the displacement while the force sensor is applied to record the reaction force. Based on the LABVIEW software we can make the boundary force data and photoelastical image visual. Photography system is used to grab real-time image of the force chain in the granular system during the loading process, the direct observation of the bearing construction and distribution of the internal force chain in the granular system is realized by the use of the photography system. According to the result contrast analysis between physical experiment and numerical simulations, we verify the validity and accuracy of the granular material photoelastic device.

To acquire a better understanding of how individuals adapt to knee osteoarthritis (KOA) and assess the effect of TKA, 3D gait analysis was conducted 17 pre-TKA KOA patients, 10 post-TKA KOA patients and 12 age-matched control subjects. Principle component analysis was used to extract waveform characteristics. Improved function was observed after TKA, but the overall lower limb capacity of post-TKA patients at 4 month post-surgery was still far below that of the control subjects. Post-TKA patients were characterized by reduced knee flexion, delayed joint motion and more gentle moments and ground reaction curves compared to controls.

As one of the most frequently used grafts in anterior cruciate ligament (ACL) reconstruction, hamstring tendon (HT) grafts are prepared with different lengths and fixed by specific fixations in knee joints. However, there are incomplete studies to investigate both the joint kinematics and graft biomechanics in the ACL reconstructions with different HT graft lengths. In this paper, three different graft lengths (i.e., 30, 50, and 70 mm) were developed in the ACL reconstruction and analyzed using finite element method under two usual clinical test loads (i.e., 134 N anterior tibial drawer and pivot shift test load). The different mechanical properties of the corresponding fixations were also considered for each graft length. It was revealed that the change in HT graft length would cause different strain and stress results in the grafts, but did not greatly influence joint stabilities under the two clinical test loads. The graft reaction force at the femoral fixation was always greatly lower than that at the tibial fixation regardless of load and graft length. The comparison of stress and strain results also indicated that more graft tissues inside the femoral and tibial tunnels could decrease the stress and strain values at the femoral and tibial fixation sites, respectively.

To compare and estimate the diagnostic value and characteristic of different diagnostic methods (blood laboratory test, histological analysis, synovial fluid cytological test and microbiological examination) in detecting the presence of periprosthetic joint infection.Data of 52 patients underwent hip or knee joint revision in Peking University People's Hospital Arthritis Clinic and Research Center between July 2013 and March 2015 were analyzed retrospectively. For each patient, results of blood laboratory tests(peripheral-blood white blood cell, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (Hs-CRP)), histological analysis, synovial fluid white cell count (SWCC), microbiological examinations (synovial fluid, tissue and prosthetic joint sonication fluid) were collected. Data were analyzed by t-test, independent sample median test or χ(2) test, respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for each method were calculated and compared by receiver operating characteristic curve.There were 30 female and 22 male patients. Twenty-one patients (40.4%) were diagnosed as PJI. The levels of CRP, ESR, IL-6 and Hs-CRP in patients with PJI were higher than that in aseptic failure patients (Z=23.084, 13.499, 5.796, 17.045, all P0.05). The sensitivities of CRP, ESR, IL-6 and Hs-CRP were 90.5%, 81.0%, 95.0% and 90.0%. The sensitivities of histological analysis and SWCC were 55.0% and 70.6%, while they had high specificity as 89.7% and 85.7%. The sensitivity of sonication fluid culture was 90.0%, which was higher than that of tissue culture (71.4%) and synovial fluid culture (65.0%) (χ(2) = 5.333, 6.400, all P0.05).The tests of CRP, ESR, IL-6 and Hs-CRP have good value in detecting PJI preoperatively. Histological analysis and SWCC have high specificity, which could help to exclude PJI. Sonication fluid culture has a higher sensitivity than tissue culture and synovial fluid culture.

The angular distribution of the 12C(7Li,6He)13N reaction at E(7Li) = 44.0 MeV was measured at the HI-13 tandem accelerator of Beijing, China. The asymptotic normalization coefficient (ANC) of 13N → 12C + p was derived to be (1.64 ± 0.11) fm−1/2 through the distorted wave Born approximation (DWBA) analysis. The ANC was then used to deduce the astrophysical S(E) factors and reaction rates for the 12C(p, γ)13N direct capture reaction at energies of astrophysical relevance.

The musculoskeletal ligament is a kind of multiscale composite material with collagen fibers embedded in a ground matrix. As the major constituent in ligaments to bear external loads, collagens are composed mainly of two collagen contents with different mechanical properties, i.e., types I and III collagen. The constitutive relation of ligaments plays a critical role in the stability and normal function of human joints. However, collagen types have not been distinguished in the previous constitutive relations. In this paper a constitutive relation for ligament tissues was modified based on the previous constitutive relation by considering the effects of collagen types. Both the collagen contents and the mechanical properties of sixteen ligament specimens from four cadaveric human knee joints were measured for determining their material coefficients in the constitutive relation. The mechanical behaviors of ligaments were obtained from both the uniaxial tensile and simple shear tests. A linear regression between joint kinematic results from in vitro and in silico experiments was made to validate the accuracy of this constitutive relation. The high correlation coefficient (R(2)=0.93) and significance (P

Angular distribution of the Li 8 ( d , p ) Li g.s. 9 reaction at E cm = 7.8 MeV was measured in inverse kinematics. The square of asymptotic normalization coefficient (ANC) for the virtual decay Li 9 → Li 8 + n was derived to be 1.33 ± 0.33 fm −1 through distorted wave Born approximation (DWBA) analysis, for the first time. According to charge symmetry, (ANC)2 for C 9 → B 8 + p was then extracted to be 1.14 ± 0.29 fm −1 . We have deduced the astrophysical S-factors and reaction rates for direct capture in B 8 ( p , γ ) C 9 at energies of astrophysical relevance using the ANC for C 9 → B 8 + p extracted from the mirror system.

The 13C(7Li, 6He)14N reaction is measured at E(7Li) = 34 MeV with the Q3D magnetic spectrometer of HI-13 tandem accelerator. Angular distributions at forward angles for proton transfer to the ground and the first excited states in 14N are obtained. In addition, angular distribution for 7Li + 13C elastic scattering is also measured. The optical potential parameters for the entrance and exit channels of the transfer reactions are derived by fitting the 7Li + 13C and 6Li + 14N elastic scattering experimental data, and their angular distributions are well reproduced by the distorted wave Born approximation calculations. A phase shift of about 2° between the calculations and the experiment data has been found in the earlier (7Li, 6He) study, whereas no such phase shift is observed in the present work.

The 13C(α, n)16O reaction is believed to be the main neutron source reaction for the s-process in asymptotic giant branch (AGB) stars. The astrophysical S-factors of this reaction have been determined based on an evaluation of the α spectroscopic factor of the 1/2+ subthreshold state in 17O (Ex = 6.356 MeV) by using the 13C(11B, 7Li)17O α transfer reaction. Our result confirms that the 1/2+ subthreshold resonance is dominant for the 13C(α, n)16O reaction at low energies of astrophysical interest.

Angular distributions for the 7Li(6Li, 7Li)6Li elastic-transfer reaction have been measured with the Q3D magnetic spectrograph at the HI-13 tandem accelerator of Beijing, China. The neutron spectroscopic factors of 7Li are derived by comparing the calculated differential cross sections, which are obtained through the distorted-wave Born approximation (DWBA) calculation, to the experimental data. And these spectroscopic factors are then used to deduce the direct capture cross sections in 6Li(n, γ)7Li at energies of astrophysical relevance.

The HI-13 tandem accelerator in the China Institute of Atomic Energy (CIAE) is a multi-user facility. Only a small part of the beam time can be used for AMS. So, it is impossible to measure very many samples and to carry out wider applications by using the HI-13 tandem AMS system. Therefore, we focus our studies on the development of measurement and detection methods and several interesting applications utilizing the long-lived radionuclides 26Al, 41Ca, 36Cl and 79Se.

The Dabieshan area between the Sino‐Korean and Yangtze cratons in east-central China has become the focus of much recent attention because of the discovery of abundant coesite and rare micro-diamond inclusions in both eclogites and their enclosing country rocks. The Dabieshan metamorphic complex, previously regarded as Archean continental basement of the Yangtze craton, is mainly made up of Precambrian felsic orthogneiss, amphibolite, and migmatitic gneiss with minor eclogite, granulite, ultramafic rock and marble. Our geochemical analyses and Nd‐Sr isotope data show that most Dabieshan orthogneisses are distinctly different from the nearby Kongling gneisses of the Yangtze basement, which are Archean high-Al TTG rocks with an average Nd model age of 3.39 0.2 Ga with volcanic arc granitic affinity. The protoliths of the Dabieshan orthogneisses are diverse, and three types of rocks are distinguished: (1) the majority of the felsic gneisses in the eclogite units display geochemical signatures of post-Archean granites and may have resulted from Neoproterozoic magmatism in a rift environment; (2) some of the felsic gneisses in the eclogite units have an affinity with Kongling gneiss, and were presumably derived from the Yangtze basement by tectonic extrusion during Mesozoic exhumation of the ultrahigh-pressure (UHP) metamorphic rocks; and (3) the felsic gneisses of the dome region show geochemical signatures of Archean granitoids and Nd model ages between 3.1 and 1.0 Ga, attributed to mixing between Neoproterozoic mantle-derived material and the Archean Kongling gneisses. Numerical modeling shows that mixing between mantle-derived melts and Kongling gneiss can account for the Nd‐Sr isotopic variation of Mesozoic mafic monzodiorites in the UHP eclogite unit, implying that the Kongling complex was extended beneath the Dabieshan terrane possibly during early Mesozoic continental collision. We suggest that the dome region was originally part of the Yangtze craton, and was separated from it by Neoproterozoic rifting. The orogen was later significantly modified, especially by Jurassic‐Cretaceous migmatization and magmatism. © 2000 Elsevier Science B.V. All rights reserved.

Three groups of Mesozoic shoshonitic or high-K calc-alkaline intrusive rocks are identified in Dabieshan high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic zone, east-central China and they are related to: (I) slab breakoff; (II) magmatic underplating; and (III) doming. Group-I, the slab breakoff-type, consists of late Triassic (∼210 Ma) mafic monzodiorites. It has moderate to high Sr, and low Rb and Ba abundances, and moderate light rare earth element (LREE)/heavy rare earth element (HREE) and K/Rb ratios. Group-II, the underplating-type, consists mainly of middle Jurassic–early Cretaceous (160–120 Ma) hornblende quartz monzonitic, biotite monzogranitic, and syenogranitic plutons, characterized by relatively high LREE/HREE and K/Rb ratios, and by a large range in concentration of Sr and Ba, coupled with much smaller range in Rb. Group-III, the doming-type, is represented by Cretaceous (125–95 Ma) granitic stocks and granitic porphyry. Compared with group-II, it has high Rb, Y and HREE abundances, low Sr and Ba abundances and low LREE/HREE and K/Rb ratios. All groups have similar Nd and Sr isotopic compositions. Among the three groups, post-collisional granitoid magmatism (group-II) with ages of 160 to 120 Ma, post-dating the HP and UHP metamorphism at 245 to 220 Ma, is the most abundant in the Dabieshan area. The post-collisional granitoid plutons were initially emplaced at different levels ranging from mid-crust to near-surface. This study shows that the whole-rock chemistry of the granitoids vary systematically with crystallization pressures. For example, K2O, normative Or, Rb and Zr show the strongest increase with decreasing pressure, whereas Ba, Nb, Nd, Yb, MnO, and normative An decrease upward in the Dabie Block. It is suggested that ascent of differentiated, buoyant liquids, combined with fractionation paired with assimilation (AFC), is responsible for the vertical variation. Geological, geochemical and petrological data indicate that group-I could have been generated by partial melting of enriched subcontinental lithosphere mantle due to slab breakoff. Group-II rocks could have been produced mainly from crustal assimilation/melting and fractional crystallization of mantle-derived magmas, whereas group-III magma could have derived from anatexis of the Dabie complex and was highly evolved in a hot doming setting. The late Triassic-early Jurassic slab breakoff may be responsible for the exhumation of UHP rocks through the mantle. The voluminous granitic emplacement together with an episode of rapid denudation suggests that magmatic underplating and inflation could have played a role in the Middle Jurassic–Early Cretaceous rapid exhumation of Dabieshan.

The differential cross section for the 7Be(d, n)8B reaction at Ec.m.=5.8 MeV has been measured using a 7Be beam produced by the radioactive nuclear beam facility at the China Institute of Atomic Energy. The 8B ions were detected in full geometry with a two dimensional position sensitive ΔE-E counter telescope. The reaction cross section was determined to be 58±8 mb. The angular distribution data were analyzed with a distorted-wave Born approximation calculation. The astrophysical S17(0) factor for the 7Be(p, γ)8B reaction was derived to be 27.4±4.4 eV b through the asymptotic normalization constant extracted from the experimental data.