Ultrasound-Guided Superior Gluteal Nerve Hydrodissection in the Treatment of Deep Gluteal Syndrome

Background: Deep gluteal syndrome is a common cause of posterior hip pain. It results from peripheral nerves, such as the sciatic or superior gluteal nerve, being compressed in the deep gluteal space. Hydrodissection is a novel technique for the treatment of nerve pain due to entrapment. The use of hydrodissection for the treatment of deep gluteal syndrome has not been reported. Methods: A case report involved a 42-year-old female presenting with deep gluteal syndrome. Case report: We report, with patient consent, an ultrasound-guided superior gluteal nerve hydrodissection method used for treating the deep gluteal syndrome. A previously healthy 42-year-old female patient sought medical attention due to persistent left gluteal pain. Trials of joint injections, physiotherapy, and epidural blocks were unsuccessful. Hydrodissection under ultrasound-guidance allowed separation of the fascial plane in areas with significant neural innervation. We targeted the superior gluteal nerve with hydrodissection offering the patient immediate and persistent relief from her symptoms. Conclusion: Ultrasound-guided hydrodissection of the superior gluteal nerve offers an effective and novel diagnostic and treatment option for deep gluteal syndrome.

Effects of Spin Transition and Cation Substitution on the Optical Properties and Iron Partitioning in Carbonate Minerals

The high-pressure behavior of deep carbonate dictates the state and dynamics of oxidized carbon in the Earth's mantle,playing a vital role in the global carbon cycle and potentially influencing long-term climate change.Optical absorption and Raman spectroscopic measurements were carried out on two natural carbonate samples in diamond-anvil cells up to 60 GPa.Mg-substitution in high-spin siderite FeCO_(3)increases the crystal field absorption band position by approximately 1000 cm^(-1),but such an effect is marginal at>40 GPa when entering the low-spin state.The crystal field absorption band of dolomite cannot be recognized upon compression to 45.8 GPa at room temperature but,in contrast,the high-pressure polymorph of dolomite exhibits a strong absorption band at frequencies higher than(Mg,Fe)CO_(3)in the lowspin state by 2000–2500 cm^(-1).Additionally,these carbonate minerals show more complicated features for the absorption edge,decreasing with pressure and undergoing a dramatic change through the spin crossover.The optical and vibrational properties of carbonate minerals are highly correlated with iron content and spin transition,indicating that iron is preferentially partitioned into low-spin carbonates.These results shed new light on how carbonate minerals evolve in the mantle,which is crucial to decode the deep carbon cycle.

Study on the crust-mantle structure in the central and southern parts of Shanxi

Another comparative interpretation was conducted with respect to the data from 5 DSS profiles in the central and southern parts of Shanxi, leading to the conclusion that in Linxian, Linfen and Xingtai earthquake regions, through which the five profiles pass, there exist anomalous crust mantle structure and abyssal crustal faults extending to Moho, all being regarded as the deep indications for earthquake occurrence.

Geochemical Characteristics of Volcanic Rocks from ODP Site 794,Yamato Basin:Implications for Deep Mantle Processes of the Japan Sea

Deep mantle processes and the dynamic mechanism of magmatism in the Japan Sea Basin are important processes that have not been studied in detail. In this paper, systematic evaluation of basalt samples from the ocean drilling program Site 794 in the Japan Sea was performed, which included petrography, whole-rock major- and trace-element analysis, Sr-Nd-Pb isotopic composition, and electron microprobe analysis of plagioclase and clinopyroxene. These basalts belong to the tholeiitic series with porphyritic texture and massive Ca-rich plagioclase, clinopyroxene, and minor olivine phenocrysts. The basalts are characterized as flat rare earth elements and high-field-strength elements with remarkably low ratios of （La/Yb）N （0.75-2.51）, significant positive anomalies of Ba, Sr, and Rb and no Eu anomaly （dEn = 0.99-1.36）. The samples showed relatively high 87Sr/86Sr （0.70425- 0.70522）, 207pb/204pb （15.511-15.610）, and 208pb/204pb （38.064-38.557） values and a low 143Nd/144Nd ratio （0.51271-0.51295）. The basalts from Site 794 can be divided into upper, middle, and lower volcanic rocks （UVR, MVR, and LVR） on the basis of their stratigraphic level. The MVR was geochemically derived from the depleted mantle, whereas the UVR and LVR originated from a nondepleted and relatively enriched mantle source with contributions from subducted Pacific plate fluid and sediments. Use of geothermobarometers indicates that the crystallization pressure for the UVR and LVR （6.25-11.19 kbar） was significantly higher than that of the MVR （3.48-5.84 kbar）. The UVR and LVR may have been derived from the low-degree （5%-10%） partial melting of spinel lherzolite, while the MVR originated from a shallower mantle source with a high degree （10%-20%） of partial melting. In addition, the geochemical characteristics of the samples are consistent with a younger age （13-17 Ma） and the depleted composition of the MVR and an older age （17-23 Ma） and slightly enriched composition of the UVR and LVR. Therefore, temporal changes in the mantle source from old and enriched to young and depleted and subsequently to old and nondepleted may have been associated with progressive lithospheric extension and thinning, as well as at least two episodes of diverse asthenospheric upwelling and pull-apart tectonic motion in the Yamato Basin.

In situ determination of crystal structure and chemistry of minerals at Earth's deep lower mantle conditions

Recent advances in experimental techniques and data processing allow in situ determination of mineral crystal structure and chemistry up to Mbar pressures in a laser-heated diamond anvil cell(DAC),providing the fundamental information of the mineralogical constitution of our Earth's interior.This work highlights several recent breakthroughs in the field of high-pressure mineral crystallography,including the stability of bridgmanite,the single-crystal structure studies of post-perovskite and H-phase as well as the identification of hydrous minerals and iron oxides in the deep lower mantle.The future development of high-pressure crystallography is also discussed.

Comparison of four clinical scores for the predicting lower limb deep venous thrombosis in Chinese patients

Objective：To evaluate Wells, Kahn, St.Andr 6 and Constans scores for the prediction of deep venous thrombosis in Chinese patients. Methods：One hundred and seventy-two patients, prospectively, blinded referred for evaluation with four clinical-score systems for suspected deep venous thrombosis, were examined by ultrasonography. Sensitivity, specificity, positive predictive value, negative predictive value and receiver operation curves were calculated for four clinical scores. The difference between areas of the ROC curve for each of the scores was compared with others and reference line. Results：Forty-six of 172 patients had deep venous thrombosis proven by sonography. The sensitivity, specificity, positive predictive value and negative predictive value for Wells score was 91.3%, 57.1%, 43.8% and 94.7%, respectively, for Kahn score; 65.2%, 71.4%, 45.5% and 84.9%, respectively, for St.Andr 6 score; 63%, 38.9%, 27.4% and 74.2% respectively, for Constans score; 95.7%, 34.9%, 34.9% and 95.7% respectively. Area under ROV curve of Constans score was 0.814, which was similar to that of Wells score, then followed by Kahn score and that of St.Andr 6 score was no difference with the reference line. Conclusion：Based on the results of our study, the sensitivity, negative prediction value and area under ROC curve are larger for Constans score and Wells score in Chinese hospitalized patients than that of Kahn score or St.Andr 6 score. Considering the aim of the clinical assessment, Constans score and Wells score are more efficient for Chinese hospitalized patients.

The petrographical and isotope geochemical tracers for deep ore-forming fluids from the Laowangzhai gold depoist in the northern part of the Ailao Mountains

Based on the petrological studies of wall rocks, mineralized rocks, ores and veins from the Laowangzhai gold deposit, it is discovered that with the development of silification, carbonation and sulfidation, a kind of black opaque ultracrystalline material runs through the space between grains and amphibole cleavages, which is the product of fast condensing consolidation with magma mantle fluids turning into hydrothermal crustal fluids in the process of mineralization and alteration. It is thought that the water in ore-forming fluids mainly derived from magmatic water through research on H-O isotopes, and C as well as S isotopic compositions, has clear mantle-derived characteristics, and rock (mine) stones contain high 87Sr/86 Sr ratios, low 143Nd/144 Nd ratios and high 206Pb/204 Pb ratios, which also reflects the ore-forming fluids were derived from the metasomatically enriched mantle. In combination with the features of H-O-C-S isotopes and Sr-Nd-Pb isotopes described above, the ore-forming fluids of the Laowangzhai gold deposit in the northern part of the Ailao Mountains were derived mainly from the deep interior of the mantle, and their properties were transformed from magma fluids to hydrothermal fluids in the course of metasomatism and alteration, which initiated crust-mantle contamination simultaneously to be in favor of mineralization.

IOP-lowering effects for the application of human umbilical vein in non-penetrating deep sclerostomy in rabbits

AIM: To estimate the effects of human umbilical vein (HUV) implanted under the sclera of glaucoma model on intraocular pressure (IOP) lowering and to investigate its related mechanisms METHODS: A total of 20 human umbilical veins (HUV) were collected from healthy fetus umbilical core. After the establishment of glaucoma model in rabbits, human freeze-dried umbilical vein was implanted under the sclera during NPDS, while for control group, sclerostomy was performed without implant. The formation of the filtration bleb and TOP were detected every 24 hours before surgery and on day 3, 7, 10 and 14 after surgery. Handheld pen-type Tono-pen II tonometer was used to measure TOP after topical anesthesia treatment. Each measurement has three duplicates. The incision recovery, filtration, conjunctiva congestion and anterior chamber inflammation were observed everyday after surgery. RESULTS: IOP was decreased dramatically with less inflammation than traditional sclerostomies with the application of HUV. The significant differences of IOP between the NPDS with and without HUV implant groups were shown up from 10 days after surgery. The average TOP in NPDS without HUV implant was 14.25mmHg, while for NPDS with HUV implant group, it was 12.30mmHg. This structure of filtration bleb, which allowed the aqueous humor to leave the eye, was formed for any type of surgery. However, 1-2 weeks later, filtration bleb was still Existed in the group of sclerostomy with HUV implant and more stable than that of the surgery without HUV implant. Histological observations were performed on day 3, 7 and 14 after surgery. For the eyes under sclerostomy with HUV implant, HUV lumina was shown up on 3 days after surgery with few fibroblast cells near the sclera. On 7 days after surgery, HUV lumina was stably maintained but with obvious fibroblast cells and inflammatory cell. On 14 days after surgery, HUV lumina was still clearly observed but with scarring formation, which suggests that the IOP lowering effects might result from an effective drainage structure formation. CONCLUSION: HUV might be an alternative material to make the drainage pathway for non-penetrating deep sclerostomy.

Assortment of Deep Mantle Fluids and Their Products in Kimberlites from China

Based on studies of petrography, mineralogy and mineral chemistry, deep mantle fluids and their products in kimberlites and diamonds can be assorted into the ultradeep fluid-transmitted minerals with an oxygen-free feature, the deep fluid metasomatized-minerals characterized by enrichment in TiO2, K2O, BaO, REE and Fe3+, and the deep fluid-reformed minerals. The three types show a successive descent in fluid origin depth and metasomatism strength, and they have brought forth a series of corresponding metasomatic products.

Combined effect of Traditional Chinese Medicine decoction and low-molecular-weight heparin calcium on the postoperative deep venous thrombosis in patients with lower limb fracture

OBJECTIVE: To investigate the combined effect of Traditional Chinese Medicine(TCM) decoction and low-molecular-weight heparin calcium on deep vein thrombosis(DVT) induced by surgery in patients with lower limb fracture.METHODS: Totally 86 hospitalized patients with DVT after surgery of lower limb fracture between September 2012 and January 2015 were recruited and randomly divided into control group and observation group, 43 cases in each group. The patients in the control group were treated with subcutaneous injection of low-molecular-weight heparin calcium, and those in the observation group were additionally given Danshen Injection and TCM decoction. The differences between two groups in occurrence rate, medication time, therapeutic effects,recurrence rate of thrombosis, activated partial thromboplastin time(APTT), and prothrombin time(PT) were compared.RESULTS: The occurrence rate of DVT in observation group(4.65%, 2/43) was lower than that in control group(27.91%,12/43)(P<0.05). The medication time of observation group was(6.15±2.94) d, shorter than(9.76±3.12) d in the control group(P<0.05). In observation group, 2 cases of DVT were cured(2/2); in the control group, 9 cases presented therapeutic effects and the total effective rate was 75.00%(9/12). The improvement of APTT and PT in the observation group was better than that in the control group(P<0.05).CONCLUSION: Integrative TCM decoction plus low-molecularweight heparin calcium is superior to applicaton of low-molecularweight heparin calcium alone in reducing and treating DVT in the postoperative patients with lower limb fracture.

Temperature Coefficient of Sound Velocity of Perovskite-Enstatite and Lateral Thermal Heterogeneity in Earths Lower Mantle

Using the differences of sound velocity and temperature on the Hugoniot and isoentropic state,the temperature coefficients of sound velocity of perovskite-enstatite under high pressure were obtained.For compressional,shear and bulk wave velocities,their temperature coefficients decrease from 0.386,0.251,0.255 m/(s·K)at 40 GPa to 0.197,0.131,0.162m/(S·K)at 140GPa,respectively.Extrapolating these to zero pressure results in(■K/■T)o=-0.0279 GPa·K^(-1),which is consistent very well with the value got by hydrostatic pressure experiment.On the basis of our data,we conclude that the compressional wave velocity anomaly of 0.1-0.2%in the deep lower mantle and 2%in the D″region would imply lateral thermal heterogeneity with amplitude of 53-106 K and 1066 K in these regions,respectively.

Ophiolites as Archives of Recycled Crustal Material Residing in the Deep Mantle

Deeply subducted lithospheric slabs may reach to the mantle transition zone(MTZ,410-660 km depth)or even to the core–mantle boundary(CMB)at depths of^2900km.Our knowledge of the fate of subducted surface material at the MTZ or near the CMB is poor and based mainly on the tomography data and laboratory experiments through indirect methods.Limited data come from the samples of deep mantle diamonds and their mineral inclusions obtained from kimberlites and associated rock assemblages in old cratons.We report in this presentation new data and observations from diamonds and other UHP minerals recovered from ophiolites that we consider as a new window into the life cycle of deeply subducted oceanic and continental crust.Ophiolites are fragments of ancient oceanic lithosphere tectonically accreted into continental margins,and many contain significant podiform chromitites.Our research team has investigated over the last 10 years ultrahigh-pressure and super-reducing mineral groups discovered in peridotites and/or chromitites of ophiolites around the world,including the Luobusa(Tibet),Ray-Iz(Polar Urals-Russia),and 12 other ophiolites from 8orogenic belts in 5 different countries(Albania,China,Myanmar,Russia,and Turkey).High-pressure minerals include diamond,coesite,pseudomorphic stishovite,qingsongite(BN)and Ca-Si perovskite,and the most important native and highly reduced minerals recovered to date include moissanite(Si C),Ni-Mn-Co alloys,Fe-Si and Fe-C phases.These mineral groups collectively confirm extremely high?pressures(300 km to≥660 km)and super-reducing conditions in their environment of formation in the mantle.All of the analyzed diamonds have unusually light carbon isotope compositions(δ13C=-28.7 to-18.3‰)and variable trace element contents that*d i stinguish them from most kimberlitic and UHPmetamorphic varieties.The presence of exsolution lamellae of diopside and coesite in some chromite grains suggests chromite crystallization depths around>380 km,near the mantle transition zone.The carbon isotopes and other features of the high-pressure and super-reduced mineral groups point to previously subducted surface material as their source of origin.Recycling of subducted crust in the deep mantle may proceed in three stages:Stage 1–Carbon-bearing fluids and melts may have been formed in the MTZ,in the lower mantle or even near the CMB.Stage 2–Fluids or melts may rise along with deep plumes through the lower mantle and reach the MTZ.Some minerals,such as diamond,stishovite,qingsongite and Ca-silicate perovskite can precipitate from these fluids or melts in the lower mantle during their ascent.Material transported to the MTZ would be mixed with highly reduced and UHP phases,presumably derived from zones with extremely low f O2,as required for the formation of moissanite and other native elements.Stage 3–Continued ascent above the transition of peridotites containing chromite and ultrahigh-pressure minerals transports them to shallow mantle depths,where they participate in decompressional partial melting and oceanic lithosphere formation.The widespread occurrence of ophiolite-hosted diamonds and associated UHP mineral groups suggests that they may be a common feature of in-situ oceanic mantle.Because mid-ocean ridge spreading environments are plate boundaries widely distributed around the globe,and because the magmatic accretion of oceanic plates occurs mainly along these ridges,the on-land remnants of ancient oceanic lithosphere produced at former mid-ocean ridges provide an important window into the Earth’s recycling system and a great opportunity to probe the nature of deeply recycled crustal material residing in the deep mantle

The role of fluids in the lower crust and upper mantle:A tribute to Jacques Touret

This special issue of Geoscience Frontiers is a tribute volume honoring the life and career of Jacques Touret. A set of research papers has been assembled, which broadly reflect his research interests over his 50 plus year career. These papers Focus on the role that fluids play during the Formation and evolution of the Earth＇s crust. Below I provide a brief summary of the life of Jacques Touret, along with a select bibliography of his more important papers. This is then followed by a brief introduction to the papers assembled for this special issue.

Analysis thrombolysis with anticoagulation treatment for early stage of deep vein thrombosis in the lower extremities

Objective: To explore the effect of thrombolysis with anticoagulation treatment for early stage of deep vein thrombosis of lower extremity. Methods: The clinical data of 106 patients at the early stage of deep vein thrombosis (DVT) in the lower extremities treated by thrombolysis with anticoagulation and dispersion drugs were analyzed retrospectively. Results: The thrombolytic effect was significant. After treatment, the deep veins were recanalized without regurgitation in 75.3% of the patients. The total effective rate was 100%. Only three patients had hemorrhagic complication, but none of the patients died. Conclusion: Thrombolysis with anticoagulation treatment is an effective and safe method for DVT at the early stage.

Prevention and Treatment of Deep Vein Thrombosis of the Lower Limbs in Patients with Complications after Orthopedic Trauma Surgery

Objective:To explore and analyze on how to prevent and treat deep vein thrombosis of the lower limbs in patients with complications after orthopedic trauma surgery.Methods:The research patients were selected from the cases of surgical treatment of orthopedic trauma in the hospital during the past two years,and a total of 58 patients were selected.The patients were randomly divided into two groups,with 29 patients in the control group treated with conventional clinical methods;and the other 29 patients were assigned to the experimental group,where targeted preventive and therapeutic measures were administered.During the research,the number of complications of postoperative deep vein thrombosis of the lower limbs and the corresponding treatment efficacy were compared between the two groups of patients.Results:According to the results of clinical experiments,the probability of patients in the experimental group suffering from deep vein thrombosis of the lower limbs after surgery was significantly lower than that of the control group(P<0.05);in addition,when complications of deep venous thrombosis of the lower limbs occurred,the treatment efficacy of the patients in the experimental group was 96.55%,and the treatment efficacy of the patients in the control group was 82.76%.There was a significant difference between the two groups(P<0.05).Conclusion:Through clinical experiments to study and analyze the prevention and treatment measures of deep vein thrombosis in patients with complications after orthopedic trauma surgery,this research proves that active and comprehensive preventive and treatment measures can effectively reduce the number of complications and improve surgery treatment efficacy.

In-situ Moissanite in Dunite: Deep Mantle Origin of Mantle Peridotite in Luobusa Ophiolite, Tibet

We report the discovery of an in-situ natural moissanite as an inclusion in the Cr-spinel from the dunite envelope of a chromitite deposit in Luobusa ophiolite,Tibet.The moissanite occurs as a twin crystal interpenetrated by two quadrilateral signal crystals with sizes of 17 pm × 10 μm and 20 μm × 7 μm,respectively.The moissanite is green with parallel extinction.The absorption peaks in its Raman spectra are at 967-971 cm-1,787-788 cm-1,and 766 cm-1.The absorption peaks in the infrared spectra are at 696 cm-1,767 cm-1,1450 cm-1,and 1551 cm-1,which are distinctly different from the peaks for synthetic silicon carbide.Moissanites have been documented to form in ultra-high pressure,high temperature,and extremely low fO2 environments and their 13C-depleted compositions indicate a lower mantle origin.Combined with previous studies about other ultra-high pressure and highly reduced minerals in Luobusa ophiolite,the in-situ natural moissanite we found indicates a deep mantle origin of some materials in the mantle sequence of Luobusa ophiolite.Further,we proposed a transformation model to explain the transfer process of UHP materials from the deep mantle to ophiolite sequence and then to the supra-subduction zone environment.Interactions between the crown of the mantle plume and mid-ocean ridge are suggested to be the dominant mechanism.

PRESENT LANDFORMS, ACTIVE TECTONIC ZONES, DEEP STRUCTURES AND UPLIFT MECHANISMS OF THE LONGSHOUSHAN BLOCK ON THE NORTHERN MARGIN OF THE QINGHAI—TIBET PLATEAU

Located in the northern margin of the Qinghai—Tibet Plateau, the Longshoushan Mt. is a small block between Qinghai—Tibet Landmass and Alashan Landmass.Traditional tectonic viewpoint does not consider that the Longshoushan Mt. is a single tectonic block. It is quite evident that there is only a hazy idea about the Longshoushan block. Though there is a very complex tectonic region between Qinghai—Tibet Landmass and Alashan Landmass, the Longshoushan block in the region shows unique tectonic landforms, deep structures and uplift mechanisms. Researching into the relationship between the Longshoushan block and the Qinghai—Tibet and Alashan Landmasses will contribute to the realization of boundary and orogenic belt on the northern margin of the Qinghai—Tibet block. It is a very important scientific subject.The Longshoushan Mt., longer than 150km in NWW direction and wider than 10km, is located on the northern side of Hexi corridor(100 5°～102 5°E,38 5°～39 3°N). It extends from the northwest of Zhangye to Hexibu, and from the south of Chaoshui basin to the north of Minle basin. From west to east, there are the highest peak, Dongdashan Mt.(3616m), the second peak, Dufengding(2937m) and Qianshan peak(2827m), height of the mountains is getting lower and lower, mean height above sea level is over 2000m, and relative height difference is about 1000m. The Longshoushan Mt. provides a natural defence for stopping the southward migration of sandstorm in the Hexi corridor, and forms a topographic step zone from the Alashan Plateau to the Qinghai—Tibet Plateau. In the Longshoushan area, developed landforms, such as planation surface, table\|land, terrace land, are general characters of all geomorphic units. It is shown that the Longshoushan Mt. is a intermittently uplifted block. An astonishingly similar of geometric patterns of Taohualashan Mt. and Hongshihu basin is very interesting natural landscape in the area. It is suggested that Taohualashan Mt. broke away from Hongshihu Basin in secular tectonic movement. The viewpoint is supported by major formation, lithofacies, limitation and style of active faulting. The Longshoushan block consists of two major active fault zones (the northern Longshoushan fault zone and the southern Longshoushan fault zone), the active Pingshanhu—Hongshihu fault basin belt and Taohualashan—Xieposhan tectonic uplift belt. In addition, there are the NNW\|trending West Polamading fault, NWW\|trending Maohudong fault trough, NNE\|trending Daxiahe rift valley and others on the block. the activity and formation style of these structures indicate that the block is acted not only by compressive stress, but also by tensile stress. The northern Longshoushan and southern Longshoushan fault zones are closely related to formation and evolution of the Longshoushan block, the two zones are active fault zones since late Pleistocene and boundary fault zones of the block. The genesis and activity style of the Pingshanhu\|Hongshihu basin are similar to the continental rift, which may be due to the mantle uplift.

Study on crust-mantle tectonics and its velocity structure along the Beijing-Huailai-Fengzhen profile

In order to investigate the interrelations of crust and upper mantle tectonics and its velocity distribution as well as seismicity in the Yanhuai basin and its surrounding area, a nearly EW trending Beijing Huailai Fengzhen wide angle reflection/refraction profile, which obliquely passes through seismic zone of Zhangjiakou Bohai Sea and coincides with a deep reflection profile in the Yanhuai basin, was completed recently. The results show: The crust presents layered structures and its thickness gradually increases from 35.0 km in Shunyi to 42.0 km in the west end of the profile; the interior crustal interfaces appear approximately horizontal or slowly sloping down from east to west; In the Yanhuai basin, the crust presents the characteristics of higher velocities alternating with the lower ones and the low velocity bodies obviously exist in the lower part of upper crust. Moreover, there are two deep crustal fault zones which stretch to the Moho discontinuity, are closely related with the seismicity in the Yanhuai area.

Deep mantle hydrogen in the pyrite-type FeO_(2)–FeO_(2)H system

The pyrite-type FeO_(2)and FeO_(2)H were synthesized at the pressure-temperature conditions relevant to Earth’s deep lower mantle.Through the water-iron reaction,the pyrite-phase is a good candidate to explain the chemical heterogeneities and seismological anomalies at the bottom of the mantle.The solid solution of pyrite-type FeO_(2)and FeO_(2)H,namely the FeO_(2)Hx(0≤x≤1),is particularly interesting and introduces puzzling chemical states for both the O and H atoms in the deep mantle.While the role of H in the FeO_(2)–FeO_(2)H system has been primarily investigated,discrepancies remain.In this work,we summarize recent progress on the pyrite-phase,including FeO_(2),FeO_(2)H,and FeO_(2)Hx,which is critical for understanding the water cycling,redox equilibria,and compositional heterogenicities in the deep lower mantle.

Seismic attenuation in the lower mantle beneath Northeast China constrained from short-period reflected core phases at short epicentral distances

The thermal structure of the lower mantle plays a key role in understanding the dynamic processes of the Earth's evolution and mantle convection.Because intrinsic attenuation in the lower mantle is highly sensitive to temperature,determining of the attenuation of the lower mantle could help us determine its thermal state.We attempted to constrain the attenuation of the lower mantle by measuring the amplitude ratios of p to ScP on the vertical component and s to ScS on the tangential component at short epicentral distances for seismic wave data from deep earthquakes in Northeast China.We calculated the theoretical amplitude ratios of p to ScP and s to ScS by using ray theory and the axial-symmetric spectral element method AxiSEM,as well as by considering the effects of radiation patterns,geometrical spreading,and ScP reflection coefficients.By comparing the observed amplitude ratios with the synthetic results,we constrained the quality factors as Qα≈3,000 and Qβ≈1,300 in the lower mantle beneath Northeast China,which are much larger than those in the preliminary reference Earth model(PREM)model of Qα~800 and Qβ~312.We propose that the lower mantle beneath Northeast China is relatively colder than the average mantle,resulting in weaker intrinsic attenuation and higher velocity.We estimated the temperature of the lower mantle beneath Northeast China as approximately 300–700 K colder than the global average value.