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The gut microbiome is linked to osteoporosis. Previous clinical studies showed inconsistent results. This study aimed to characterize the gut microbiota feature and reveal its relation with diet in postmenopausal osteoporosis. Fifty-five postmenopausal women with osteoporosis (Op group) and forty-four age-matched postmenopausal women (normal bone mineral density, Con group) were included in this study. Fecal microbiota was collected and analyzed by shallow shotgun sequencing. Food frequency questionnaires were collected from both groups, and Spearman analysis was used to clarify its correlation with gut microbiota. A total of 2671 species from 29 phyla, 292 families, 152 orders, 80 classes were detected in the study. The two groups had no significant difference in the α and β diversity (p > 0.05). At the genus level, Anaerostipes was enriched in Op group (p < 0.05). At species level, Methanobrevibacter smithii, Bifidobacterium animalis, Rhodococcus defluvii, Lactobacillus plantarum, and Carnobacterium mobile were enriched in the Op group, while Bacillus luciferensis, Acetivibrio cellulolyticus, Citrobacter amalonaticus, and Bifidobacterium breve were differentially enriched in the Con group. Food frequency questionnaire showed that postmenopausal women with osteoporosis intaked more red meat, beer, white and red wine (p < 0.05), and the Con group had more yogurt, fruit, and tea consumption. Red meat consumption had a significant negative correlation with Streptosporangiales (p < 0.01) and Actinomadura (p < 0.05). Fruits intake negatively correlated with Nocardiaceae, Rhodococcus, and Rhodococcus defluvii (p < 0.05). More yogurt intake was consistently correlated with a greater abundance of Streptosporangiales. This study suggests that gut microbiota is significantly altered in the postmenopausal osteoporosis population at genus and species levels, and specific dietary intake might relate to these changes. [ABSTRACT FROM AUTHOR]

The Chinese Meridian Project (CMP) is devoted to establishing a comprehensive ground-based monitoring network for China's space weather research. CMP is a major national science and technology infrastructure project with the participation of more than 10 research institutions and universities led by the National Space Science Center of the Chinese Academy of Sciences. CMP is planned to be constructed in two phases: CMP phases I and II. The first phase (CMP-I) started construction in 2008 and completed in 2012, after which it entered the operation stage. The 10-year observation of CMP-I has made significant scientific discoveries and achievements in the research fields of the middle and upper atmospheric fluctuations, metal layers in the mesosphere and lower thermosphere, ionospheric disturbances and irregularities, geomagnetic disturbances, and influences of solar activity. The review summarizes the main observations and research achievements, space weather forecast modeling and methods based on CMP-I over the past 10 years, and presents a future extension perspective along with the construction of CMP-II. [ABSTRACT FROM AUTHOR]

The geostationary orbit (GEO) satellites provide a great opportunity to continuously monitor the earth system, which has shown a powerful application in ionospheric total electron content (TEC) studies. As the GEO satellites revolve the earth over the equator synchronously with the earth's rotation, the GEO satellites appear motionless in the sky. In TEC studies, the position of the GEO satellites is normally assumed to be fixed, but the actual position changes slightly. We assess the effects of the orbital variations of the GEO satellites on monitoring ionospheric TEC based on precise satellite orbit solutions or broadcast ephemeris. The results indicate that the sub-satellite points of the GEO satellites change slightly and could induce certain variations of ionospheric pierce point (IPP). The orbital inclination and the receiver location with respect to the GEO satellite mainly determine the magnitude of IPP drift. Based on simulations with an empirical ionospheric model, the TEC differences due to the fixed GEO IPP assumption are not completely negligible. The day-to-day variations of the daily GEO IPP trajectories are not stable over a long-term time scale. The daily and yearly variations of the inclined geosynchronous orbit (IGSO) are also examined. The IGSO-based TEC could be used in the day-to-day comparison for a short period, though it is not suitable for long-term TEC studies. This work provides additional clues to improve the ionospheric studies based on GEO and IGSO TECs. [ABSTRACT FROM AUTHOR]

The ionosphere exhibits some characteristic perturbations during sudden stratospheric warming (SSW) events, of which the mechanism is not thoroughly understood. This study focuses on the latitudinal and interhemispheric differences of the enhanced semi-diurnal lunitidal (M2) perturbations related to SSW using total electron content calculated from the network of Global Navigation Satellite System and ionosonde data in the eastern Asia–Australia sector during the January 2009 SSW. Our results show that the most distinct M2 perturbations in the northern and southern hemispheres occur near the Equatorial Ionization Anomaly crest regions around ± 15° geomagnetic latitudes, but corresponds to different moon phases, respectively. Clear M2 perturbations extend to middle latitudes only in the southern hemisphere and have another local maximum in the southern middle latitude. Such latitudinal and interhemispheric features of ionospheric M2 perturbations in the low latitude in the eastern Asia–Australia sector are similar as those in the American sector during the same SSW event. This supports previous suggestion that such latitudinal and interhemispheric differences in the low latitude can be primarily explained by the summer–winter thermospheric wind modulation on equatorial plasma fountain and thus emphasize its role in the vertical coupling process of M2 perturbation. The clear differences of M2 perturbations in the southern middle latitude between the eastern Asia–Australia and American sectors indicate that the thermospheric circulation related to the Weddell Sea Anomaly may have influence on the lower atmosphere–ionosphere coupling. [ABSTRACT FROM AUTHOR]

In this paper, we describe the design and surgical process of personalised pelvic prostheses fixation through 3D printing according to different Enneking pelvic tumour zones: the ilium (Zone I), acetabulum (Zone II), and pubis and ischium (Zone III). A 3D model of the pelvis was reconstructed using imaging data, and the parameters on the planes of the acetabulum and pelvic incisal margin were measured. The main body of the pelvic prosthesis was constructed, a porous structure was designed on the bone-prosthesis interface, and the movement paths, lengths, and diameters of screws were planned. By combining the pathological model and osteotomy guide, limb salvage reconstruction was performed in patients with pelvic tumours. Preoperative and postoperative data were compared to verify the prosthesis stability. Our investigation revealed that the long-term survival of pelvic reconstruction prostheses depends on accurate matching with the bone defect area, good initial stability, and a porous structure to allow bone ingrowth. [ABSTRACT FROM AUTHOR]

Background: Prosthetic reconstruction may be a promising treatment for peri-acetabular malignant bone tumour; however, it is associated with a high complication rate. Therefore, prosthetic design and approach of prosthetic reconstruction after tumour resection warrant study.Methods: We retrospectively analyzed 11 patients with peri-acetabular malignant bone tumours treated by personalized 3D-printed hemipelvic prostheses after en bloc resection between 2015 and 2016. Pre-operative and post-operative pain at rest was assessed according to a 10-cm VAS score. The results of functional improvement were evaluated using the MSTS-93 score at the final follow-up. We also analyzed tumour recurrence, metastases, and complications associated with the reconstruction procedure.Results: All patients were observed for six to 24 months with an average follow-up of 15.5 months. One patient had occasional pain of the involved hip at the final follow-up (VAS, pre vs. post 8 months: 3 vs. 2). The mean MSTS-93 score was 19.2 (range, 13-25). Hip dislocation was detected in two patients, while delayed wound healing occurred in one patient. One patient with mesenchymal chondrosarcoma had a left iliac bone metastasis. Local tumour recurrence was not observed.Conclusions: Reconstruction of bony defect after tumour resection using personalized 3D-printed hemipelvic prostheses can obtain acceptable functional results without severe complications. Based on previous reports and our results, we believe that reconstruction arthroplasty using 3D-printed hemipelvic prostheses will provide a promising alternative for those patients with peri-acetabular malignant bone tumours.Level Of Evidence: Level IV, therapeutic study. [ABSTRACT FROM AUTHOR]

The present paper investigates the asymmetrical variability of the location of the north and the south equatorial ionization anomaly (EIA) crests in the East-Asian sector, along with their association with simultaneous observations of equatorial electrojet (EEJ) strength, geomagnetic activity index, and solar flux index during the 2002-2003 sudden stratospheric warming (SSW) event. Analysis of these observations indicates the existence of a large-scale quasi 16-day periodic meridional movement in both EIA crests, and also reveals a strong correlation between the quasi 16-day oscillation in geomagnetic latitudes of the EIA crest and EEJ strength. The latitude of the northern/southern EIA crest and the EEJ strength indicate that obvious synchronous periodic oscillations were in-phase in the northern and southern hemisphere when the SSW occurred. In addition, it is also found that both the EIA crest location and amplitude of the periodic movement of the EIA locations exhibit hemispheric asymmetry. The amplitude of the periodic movement of the EIA location in the southern hemisphere is larger than that of the northern hemisphere, and the southern EIA crest is further off from the equator than the north one. Understanding these asymmetries requires a combination of mechanisms that involve at least trans-equator meridional winds and the position of a sub-solar point; however, potential disturbances in neutral winds associated with the SSW may additionally complicate the equatorial ionospheric dynamics. [ABSTRACT FROM AUTHOR]

The classical multidimensional scaling (MDS) method is introduced and applied in the study of the hour-to-hour ionospheric variability based on the ionospheric foF2 observed at three ionosonde stations in East-Asia in 2002 and 2007. Results from the matrix eigen decompositions indicate that the annual part of the ionospheric variation is large in middle latitude and solar maximum period (2002) while low in the low latitude and solar minimum period (2007). The connectivity maps of the hour-to-hour ionospheric variability based on MDS method show some common diurnal features. The ionospheric connectivity between adjacent hours near noon hours and near midnight hours is high. The ionospheric connectivity between adjacent hours near sunrise hours and near sunset hours is poor, especially for the sunrise hours. Also there are latitudinal and solar activity dependences in this kind of connectivity. These results revealed from the ionospheric connectivity maps are useful physically and in practice for the ionospheric forecasting on the hour-to-hour scale. [ABSTRACT FROM AUTHOR]

In this work, the ionospheric variability is analyzed by applying the wavelet decomposition technique to the noontime foF2, F10.7, interplanetary magnetic field (IMF) Bz, Ap, and lower thermospheric temperature at pressure of 10 hPa in 2002. Results show that the variance of periodic oscillations in the ionosphere is largest in the 2-4-day period and declines with the increase of the period. The maximum variance of the periodic oscillations in solar irradiation is in the 16-32-day period. For geomagnetic activities, most of the variance is about equally distributed on intervals of periods shorter than 32 days. Variance distributions of IMF Bz and lower thermospheric temperature are similar to those of the ionosphere. They show the maximum in the 2-4-day period and decline with the increase of the period. By analyzing the distributions of the variances, the potential connections between the ionosphere and the external sources are discussed. [ABSTRACT FROM AUTHOR]

Based on the analysis of the satellite DCB data estimated by our method and the Center for Orbit Determination in Europe (CODE) from 1999 to 2011, the features of the temporal variation of differential code biases (DCB) are studied. Summarily, there are three types of variations in DCB on different time scales. The first one is the day-to-day variation that exhibits more obviously in solar maximum years. The second one is the variation with about one year periodic variation that behaves more obviously from 1999 to 2004. The last one is the monotonously descending tendency from 1999 to 2010. Considering the basic ionospheric approximation in DCB estimation method, the features of the variability of the ionospheric morphology from 1999 to 2010 are also displayed based on the ionospheric characteristic parameters. It can be concluded that the day-to-day and annual variation of the estimated global positioning system (GPS). DCB is related to the ionospheric variability. The variation of DCBs on solar cycle time scale includes the real hardware DCBs and pseudo-DCBs induced by ionospheric variation. No doubt, these kinds of 'pseudo' variations of DCB will affect the precision of ionospheric total electron content (TEC) derived from the GPS data. In addition, this study is helpful for evaluating the influence of ionospheric weather on TEC derivation and is also useful for developing one estimation method of DCB with more stability and precision through introducing a more practical ionospheric model. [ABSTRACT FROM AUTHOR]

Ionospheric disturbances are the main causes of space weather events, which seriously influence accurate navigation, telecommunication, and so on. It is a fundamental issue to detect and analyze the disturbance processes of the ionosphere. Theoretically, the understanding of the mechanisms of most ionospheric disturbances depends on observational results. With the development of space observation techniques and related equipments, various efforts have been made to analyze the long-term statistical variations as well as sudden disturbances of ionospheric observation results. We briefly report some research progresses of ionospheric disturbances achieved in recent years, with regard to ground-based and satellites observations. The purpose is to provide a reference about the latest research progresses and improve the development of the future ionospheric disturbances observations and related researches. [ABSTRACT FROM AUTHOR]

Particle bursts (PBs), the phenomena characterized by short-term increases of particle counting rates (CRs), were observed by space-borne radiation belt particle detectors. With the electron CR data obtained by National Oceanic and Atmospheric Administration (NOAA)-18 satellite, the occurrence of PBs in the inner belt (1⩽ L⩽2 and B⩾20.5 μT) were derived for years 2006-2011. The monthly occurrence number of PBs exhibits a strong maximum in northern summer (May-August). In association with global lightning data, the seasonal occurrence of PBs is found to be consistent with the lightning activity, especially if only lightning flashes at latitudes >20° are taken into account. The positive correlation between PBs and mid-latitude lightning discharges indicates the role of lightning-induced whistler waves, and is consistent with the expected pitch-angle scattering by wave-particle interactions. The contribution of lightning is so significant that it forms a non-negligible seasonal background of PBs. If one connects PBs to seismoelectromagnetic emissions (SEME) in attempt to find the earthquake precursor, the lightning background needs to be considered with great care. [ABSTRACT FROM AUTHOR]

High bone mineral density (BMD) has been associated with increased breast cancer in prospective studies of postmenopausal women, but the real relationship is still controversial. Therefore, we undertook a meta-analysis to evaluate the association between BMD and the risk of breast cancer in postmenopausal women. We performed systematic searches on MEDLINE, EMBASE, and OVID. Data extraction was performed independently by two reviewers. For each study, we extracted the relative risks (RRs) and 95 % confidence intervals (CIs) for categorical variables and per standard deviation (SD) increases in BMD. Heterogeneity, publication bias, and subgroup analysis were performed. The analysis included 70,878 postmenopausal women from 10 studies with 1,889 breast cancers during a mean follow-up of 6 years (range 3.2-8.4 years). The summary RRs for the highest versus lowest categorical variable showed that higher BMD in the hip (RR 1.62; 95 % CI: 1.17-2.06) and in the spine (RR 1.82; 95 % CI: 1.07-2.57) were associated with a 62 and 82 % increased risk of breast cancer. Per SD, increase in hip BMD and spine BMD were also associated with a higher risk of breast cancer (RR for hip BMD 1.20; 95 % CI: 1.09-1.31 and RR for spine BMD 1.26; 95 % CI: 1.10-1.41). In this meta-analysis, a higher BMD was found to be associated with a significantly higher risk of breast cancer in postmenopausal women. [ABSTRACT FROM AUTHOR]

From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events. During this period, one large positive ionospheric storm happened over the East-Asian region on Nov. 8, 2004. On Nov. 10, 2004, a strong spread-F was observed by the ionosonde located in the mid-latitude region of East China and Japan, and the ionospheric fluctuation over the ionosonde stations derived from GPS observation was also obvious. In this report, the characteristics of the spatial distribution of the ionosphere fluctuation and its temporal evolution are studied using the parameter of the rate of total electron content (ROT) derived from dual-frequency GPS measurement. Strong fluctuating activity of the ionosphere was found over the mid-latitude region in the southern and northern hemispheres between longitudes of 100°E and 180°E during the magnetic storm period on Nov. 10, 2004, and a regular movement of the disturbing region was observed. In the end, the reason of the ionospheric fluctuation during this magnetic storm is analyzed. [ABSTRACT FROM AUTHOR]

In this paper, we focus on ionospheric absorption in the East Asia sector, and look for manifestations of atmospheric influences in this area. First, a 4-year historical record of absorption measurement at Beijing is presented. This record was obtained by a sweep frequency technique, in which 27-days periodic variation of the absorption level was found to be dominant, appearing in most seasons except winters. Instead, unusual enhancements of the absorption level appeared in winters (winter anomaly), at the meantime the level varied with periods mainly in the range of 8-12 days. Comparing to 27-days period from the Sun, the shorter period oscillations should be related to planetary wave activities in lower atmosphere. Second, f data from 5 mid-latitude ionosondes in Japan were used as an indirect but long-term measurement. With the f data covering two solar cycles, disturbances with various periods were found to be active around solar maximum years, but the 8-12 days oscillations always existed in winter, showing seasonal dependence instead of connection to solar activity. These results given in this paper demonstrate seasonal and solar cycle-dependent features of the ionospheric absorption in East Asia sector, and confirm the existence of influence from atmosphere-ionosphere coupling in this area, as well as the relationship between ionospheric winter anomaly and planetary wave activity. [ABSTRACT FROM AUTHOR]

The measurement of the electron radiation inside the satellite is important for engineering and space environment researches. The particle radiation detectors (PRD) on board CBERS-1 and CBERS-2 made great contribution to understanding of the space environment. Then, what is the radiation relationship between inside and outside the satellite? The Monte Carlo simulation with Geant4 was implemented to study the problem. The boundaries of the energy bins of 0.5 and 2 MeV were precisely corresponding to outside energies of 0.99 and 2.52 MeV, respectively. Besides the changes of the energy bins, the fluxes inside were smaller than those of the corresponding bins outside. The spectrum inside the satellite was harder than that outside. An indicator was that the flux ratio of the high energy bin to the low energy bin increased more than 20% from outside to inside. The geometric factor (GF) relates to the incident energy of electrons. By using the AE-8 model to derive the incident spectrum, the GFs of the low and high energy bins were 1.15 and 0.70 cm sr, respectively. GF of the low energy bin was larger than that of the high energy bin. But they were both smaller than the previous results. It was due to the scattering, straggle and shielding effects. [ABSTRACT FROM AUTHOR]

One of the most fundamental important issues in the space physics is to understand how solar wind energy transports into the inner magnetosphere. Ultra low frequency (ULF) wave in the magnetosphere and its impact on energetic particles, such as the wave-particle resonance, modulation, and particle acceleration, are extremely important topics in the Earth’s radiation belt dynamics and solar wind—magnetospheric coupling. In this review, we briefly introduce the recent advances on ULF waves study. Further, we will explore the density structures and ion compositions around the plasmaspheric boundary layer (PBL) and discuss its possible relation to the ULF waves. [ABSTRACT FROM AUTHOR]

The relationship of daily accumulated cycle slip occurrence with the season is analyzed using the GPS data observed in six GPS stations located in China low latitude region in 2001. It is found that the seasonal dependence of cycle slip occurrence is evident. The cycle slip mainly occurs during the periods of two equinox months (March to May and September to October), and some correlative changes of the cycle slip occurrences over all six stations are exhibited in some special days. Considering the diurnal dependence of cycle slip, it can be inferred that the cycle slip occurrence with certain elevation limitation is related with the ionospheric irregularities over this region. [ABSTRACT FROM AUTHOR]

Based on the knowledge and related theory of earth’s radiation belt, the data of energetic particles observed by detectors onboard ‘CBERS-1’ satellite at a solar synchronous orbit were analyzed. It is proved that the observational results are in agreement with the theoretical description of the radiation belt structures. Analysis of more than 3 years’ data showed clearly that under quiet solar conditions, at a height of about 800 km the energetic particles were mainly located in three regions: northern auroral belt (40°–80°), southern auroral belt (−40°–−80°) and South Atlantic Geomagnetic Anomaly Region (SAA). Actually, this is for the global distribution, at each longitude the latitudinal coverage is much narrower and particles are along the geomagnetic latitude of about ±60°. The species of particles in different regions and their counting rates are different. In SAA, usually both electrons and protons are observed, which should come from inner radiation belt; in polar regions only energetic electrons are observed under the quiet condition, which belongs to the outer radiation belt. The distribution of outer radiation electrons is asymmetrical for longitudes as well as northern and southern polar regions. These asymmetries can be explained with the reflecting altitudes of the mirror points of charged particles at the same L shell. [ABSTRACT FROM AUTHOR]

A climatological survey of Martian ionospheric plasma density irregularities was conducted by exploring the in-situ measurements of the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. The irregularities were first classified as enhancement, depletion, and oscillation. By checking the simultaneous magnetic field fluctuation, the irregularities have been classified into two types: with or without magnetic signatures. The classified irregularities exhibit diverse global occurrence patterns, as those with magnetic signatures tend to appear near the periphery of the crustal magnetic anomaly (MA), and those without magnetic signatures prefer to appear either inside of the MA or outside of the MA, depending on the type and solar zenith angle. Under most circumstances, the irregularities have a considerable occurrence rate at altitudes above the ionospheric dynamo height (above 200 km), and the magnetization state of the ions seems irrelevant to their occurrence. In addition, the irregularities do not show dependence on magnetic field geometry, except that the enhancement without magnetic signatures favors the vertical field line, implying its equivalence to the localized bulge. Other similarities and discrepancies exist in reference to previous studies. We believe this global survey complements previous research and provides crucial research clues for future efforts to clarify the nature of the Martian ionospheric irregularities. [ABSTRACT FROM AUTHOR]

Spread-F is a manifestation of ionospheric irregularities and generally takes place at nighttime. However, it can also be observed seldom at daytime. It is recognized that acoustic gravity waves (AGWs) play an important role in triggering plasma instability which results in spread-F in the ionosphere. The typhoon is a main source of the AGWs. In this paper, two cases of ionospheric daytime spread-F in the period of typhoon were analyzed. One case was on July 29, 1988 and the other was on August 01, 1989. The results showed the following: 1) There were some wave-like disturbances appearing in the HF Doppler records firstly, consequently the Doppler echo traces became scattered, which indicated that the ionospheric spread-F was triggered; 2) the blurred echo traces in the both two cases appeared in the morning (08:30-11:30 Beijing time) and lasted for more than two hours; 3) with the blurred echoes gradually weakening, the traveling ionospheric disturbances (TIDs) still existed and became clearer; 4) the frequency shifts in the two cases were both positive, implying the effective reflecting surface of the radio wave in the ionosphere moved downwards. These results provide good observational evidence for daytime spread-F during the typhoon period in Asian region. [ABSTRACT FROM AUTHOR]