Surgical treatment of osteogenesis imperfecta: a summary of the incidence of femoral implant-related complications in children with Sillence type I, III and IV.

PURPOSE: This study explored the incidence of IRCs used in the procedures of the femur in children with osteogenesis imperfecta (OI) and investigated the independent risk factors of IRCs. METHODS: Three hundred eight-eight cases of surgical data about children with OI were included, who were treated with plate, elastic nail, Kirschner wire and telescopic rod. The choice of different procedures depended on the age of children, the status of femur and the availability of devices. Patient demographics and major IRCs were recorded to compare the outcomes of the four procedures. Then, Cox proportional hazard regression was used to analyse the independent risk factors of IRC, and subgroup analysis was applied to further verify the above results. RESULTS: The total incidence of IRC in the four groups was 90.1% (191/212) for plate, 96.8% (30/31) for Kirschner wire, 87.7% (57/65) for elastic nail and 30.0% (24/80) for telescopic rod. The incidence of IRC in the telescopic rod was lower than that in plate, elastic nail and Kirschner wire (P < 0.001). Cox proportional hazard regression analysis confirmed that procedure was the independent risk factor of IRC (HR, 0.191; 95% CI, 0.126-0.288; P < 0.001), fracture (HR, 0.193; 95% CI, 0.109-0.344; P < 0.001) and deformity (HR, 0.086; 95% CI, 0.027-0.272; P < 0.001). In addition, age of surgery was the independent risk factor of fracture (HR, 0.916; 95% CI, 0.882-0.952; P < 0.001) and deformity (HR, 1.052; 95% CI, 1.008-1.098; P = 0.019). Subgroup analysis confirmed that age of surgery, gender, classification, preoperative state and angle did not affect the effect of telescopic rod on reducing the risk of IRCs. CONCLUSIONS: In our cohort, lower incidence of IRCs was observed in telescopic rod group compared with plate, Kirschner wire and elastic nail. Procedure and age of surgery were independent risk factors of fracture. Likewise, procedure and age of surgery were independent risk factors of deformity, and procedure was independent risk factors of IRC.

On the error performance and channel capacity of a uniquely decodable coded FSO system over Malaga turbulence with pointing errors.

Our previous work has proved that the uniquely decodable code (UDC) has the ability of enhancing the throughput of a free space optical communication (FSO) system. This paper quantitatively analyzes the error performance and channel capacity of the UDC-FSO system under Malaga turbulence and pointing errors. We first propose the minimum distance of the superimposed patterns (MDSP) approximation to reveal the universal symbol error rate (SER) for UDC-FSO systems. A closed form expression of SER is further deduced for a special case of 2 TXs. Based on the deduced SER, the upper and lower bounds of bit error rate (BER) can be obtained. Additionally, the discrete channel capacity of the UDC-FSO system is defined and deduced according to different superposition patterns, as well as the channel capacity gain. Both simulation and experiment verify the accuracy of the MDSP and SER's expressions. It's also discovered that the channel capacity of the UDC-FSO system is superior to the conventional end-to-end (E2E) link, where maximal channel capacity is limited by the UDC codebooks.

Which is the best femoral implant in children with osteogenesis imperfecta? a retrospective cohort study of 783 procedures.

BACKGROUND: Osteogenesis imperfecta (OI) is a hereditary genetic disorder characterized by bone fragility and extremity deformities. The surgical management for long-bone fractures and deformities in OI remains a challenge. We aimed to compare clinical outcomes after femoral surgery splinted with the telescopic rod, the plate and screws, the elastic nail and the non-elongating rod in setting of OI. METHODS:  A retrospective cohort study included 783 femoral procedures (mean age 6.00 (interquartile range (IQR) 5.00) years, 335 (42.8%) females) was conducted, and individuals were categorized into four groups according to implants. After verifying comparability among the groups, revision rate and implant survival period were compared among the Sillence types and the same comparison were made among four groups within each Sillence type. The incidence of refractures, deformities, and implant-related complications were also compared among the four groups. RESULTS: There were no significant differences in demographic information among the four groups in terms of sex (p = 0.101), laterality (p = 0.587), Sillence type (p = 0.122), and postoperative follow-up period (p = 0.214). In total, children with Sillence type III had the highest revision rate and the shortest implant survival period; children with Sillence type I had the lowest revision rate and the longest implant survival period; and children with Sillence type IV had the revision rate and the implant survival period between those observed in Sillence types I and III. In Sillence types III and IV, the telescopic rod had lower revision rate (III 24.8%; IV 20.9%) compared to the plate (III 97.2%, p<0.001; IV 80.3%, p<0.001), the elastic nail (III 100.0%, p=0.019; IV 73.9%, p<0.001) and the non-elongating rod (III 65.0%, p<0.001; IV46.9%, p<0.001); the median implant survival period of the telescopic rod (III 48.00 (IQR 28.50) months; IV 43.00 (33.00) months) is longer than the plate (III 11.00 (9.00) months, p<0.001; IV 19.00 (20.00) months, p<0.001), the elastic nail (III 45.00 (37.75) months, p=1.000; IV 19.00 (35.00) months, p=0.028) and the non-elongating rod (III 39.00 (31.75) months, p=0.473; IV 38.50 (29.75) months, p=1.000).A similar trend was observed in Sillence type I (p = 0.063, p = 0.003; respectively). In addition, the incidence of refracture (15.5%), deformity (2.8%) and implant-related complications (23.1%) were also statistically lower in the telescopic rod group. CONCLUSION: In our cohort, lower revision rate and longer implant survival period were observed in telescopic rod group. This was mainly due to the significant lower incidence of refracture, deformity and implant-related complications with the use of telescopic rod.

Non-Iterative Multiscale Estimation for Spatial Autoregressive Geographically Weighted Regression Models.

Multiscale estimation for geographically weighted regression (GWR) and the related models has attracted much attention due to their superiority. This kind of estimation method will not only improve the accuracy of the coefficient estimators but also reveal the underlying spatial scale of each explanatory variable. However, most of the existing multiscale estimation approaches are backfitting-based iterative procedures that are very time-consuming. To alleviate the computation complexity, we propose in this paper a non-iterative multiscale estimation method and its simplified scenario for spatial autoregressive geographically weighted regression (SARGWR) models, a kind of important GWR-related model that simultaneously takes into account spatial autocorrelation in the response variable and spatial heterogeneity in the regression relationship. In the proposed multiscale estimation methods, the two-stage least-squares (2SLS) based GWR and the local-linear GWR estimators of the regression coefficients with a shrunk bandwidth size are respectively taken to be the initial estimators to obtain the final multiscale estimators of the coefficients without iteration. A simulation study is conducted to assess the performance of the proposed multiscale estimation methods, and the results show that the proposed methods are much more efficient than the backfitting-based estimation procedure. In addition, the proposed methods can also yield accurate coefficient estimators and such variable-specific optimal bandwidth sizes that correctly reflect the underlying spatial scales of the explanatory variables. A real-life example is further provided to demonstrate the applicability of the proposed multiscale estimation methods.

Likelihood based synchronization algorithms in optical pulse position modulation systems with photon-counting receivers.

Deep space optical communication (DSOC) is becoming a hot topic. Pulse position modulation (PPM) is an effective tool to realize DSOC benefiting from the feature of high sensitivity. In this paper, we analyze 2 × 1 optical PPM systems with photon-counting detectors, where the distance difference between the two links causes asynchronous superpositions at the receiving end. Two synchronization algorithms are proposed to estimate the time offsets of the two links, which are the optimal Global Maximum Likelihood Estimation (GMLE) and the suboptimal Integer Comparison - Fractional Likelihood Estimation (ICFLE). The complexities of the two methods are also compared. In order to measure the two proposed algorithms, the Cramer-Rao bounds (CRB) are derived. According to simulation results, both the two proposed algorithms approach the deduced CRBs. Furthermore, an equivalent experiment is designed to verify the feasibility and effectiveness of the proposed algorithms. It's also indicated that the proposed algorithms may be utilized in practical systems.

High-Precision Log-Ratio Spot Position Detection Algorithm with a Quadrant Detector under Different SNR Environments.

In atmospheric laser communication, a beam is transmitted through an atmospheric channel, and the photocurrent output from a quadrant detector (QD) used as the tracking sensor fluctuates significantly. To ensure uninterrupted communication and to adapt to such fluctuations, in this paper we apply logarithmic amplifiers to process the output signals of a QD. To further improve the measurement accuracy of the spot position, we firstly propose an integral infinite log-ratio algorithm (IILRA) and an integral infinity log-ratio algorithm based on the signal-to-noise ratio (BSNR-IILRA) through analysis of the factors influencing the measurement error considering the signal-to-noise ratio (SNR) parameter. Secondly, the measurement error of the two algorithms under different SNRs and their variations are analyzed. Finally, a spot position detection experiment platform is built to correctly and efficiently verify the two algorithms. The experimental results show that when the SNR is 54.10 dB, the maximum error and root mean square error of the spot position of the IILRA are 0.0054 mm and 0.0039 mm, respectively, which are less than half those of the center approximation algorithm (CAA). When the SNR is 23.88 dB, the maximum error and root mean square error of the spot position of the BSNR-IILRA are 0.0046 mm and 0.0034 mm, respectively, which are one-thirtieth and one-twentieth of the CAA, respectively. The spot position measurement accuracy of the two proposed algorithms is significantly improved compared with the CAA.

Molecular Insight into the Binding of Astilbin with Human Serum Albumin and Its Effect on Antioxidant Characteristics of Astilbin.

Astilbin is a dihydroflavonol glycoside identified in many natural plants and functional food with promising biological activities which is used as an antioxidant in the pharmaceutical and food fields. This work investigated the interaction between astilbin and human serum albumin (HSA) and their effects on the antioxidant activity of astilbin by multi-spectroscopic and molecular modeling studies. The experimental results show that astilbin quenches the fluorescence emission of HSA through a static quenching mechanism. Astilbin and HSA prefer to bind at the Site Ⅰ position, which is mainly maintained by electrostatic force, hydrophobic and hydrogen bonding interactions. Multi-spectroscopic and MD results indicate that the secondary structure of HSA could be changed because of the interaction of astilbin with HSA. DPPH radical scavenging assay shows that the presence of HSA reduces the antioxidant capacity of astilbin. The explication of astilbin-HSA binding mechanism will provide insights into clinical use and resource development of astilbin in food and pharmaceutical industries.

Design and experimental demonstration of 8-QAM coherent free-space optical communication using amplitude compensation and phase recovery.

In this paper, a new, to the best of our knowledge, scheme is proposed to mitigate the atmospheric turbulence effect in coherent free-space optical (FSO) communications with 8-quadrature amplitude modulation by employing amplitude compensation and phase recovery. The amplitude compensation and phase recovery algorithm in the scheme can significantly improve system performance without acquiring instantaneous channel state information or probability density function of a turbulence model. Numerical studies show that the bit error rate of the proposed scheme is four orders of magnitude lower than that of the system without any algorithm over a lognormal turbulence channel with normalized standard deviation of irradiance σ=0.25 and phase noise with normalized variance σϕ2=0.07, when the frequency offset fo=20MHz, combined linewidth Δf=10kHz, and average signal-to-noise ratio γ=20dB. Experiments are also carried out to investigate the performance of the scheme, and the results prove its superiority. Hence, this scheme can contribute to practical realization of the FSO system.

Feasibility of Laser Communication Beacon Light Compressed Sensing.

The Compressed Sensing (CS) camera can compress images in real time without consuming computing resources. Applying CS theory in the Laser Communication (LC) system can minimize the assumed transmission bandwidth (normally from a satellite to a ground station) and minimize the storage costs of beacon light-spot images; this can save more than ten times the typical bandwidth or storage space. However, the CS compressive process affects the light-spot tracking and key parameters in the images. In this study, we quantitatively explored the feasibility of the CS technique to capture light-spots in LC systems. We redesigned the measurement matrix to adapt to the requirement of light-tracking. We established a succinct structured deep network, the Compressed Sensing Denoising Center Net (CSD-Center Net) for denoising tracking computation from compressed image information. A series of simulations was made to test the performance of information preservation in beacon light spot image storage. With the consideration of CS ratio and application scenarios, coupled with CSD-Center Net and standard centroid, CS can achieve the tracking function well. The information preserved in compressed information correlates with the CS ratio; higher CS ratio can preserve more details. In fact, when the data rate is up than 10%, the accuracy could meet the requirements what we need in most application scenarios.

Laser communication pointing errors caused by bending deformation of the altitude axis of a T-shaped altitude-azimuth mount.

A T-shaped altitude-azimuth mount is used as a platform for laser communication terminal equipment, and its pointing accuracy has an important influence on the link establishment, stable operation, and communication quality of laser communication. The bending deformation of the altitude axis is an important factor affecting the pointing accuracy of a T-shaped altitude-azimuth mount. In this paper, the bending deformation angle of the altitude axis caused by the load gravity was calculated by applying cantilever beam deformation theory, and the mathematical models of the pointing errors caused by bending deformation of the altitude axis were derived by using spherical trigonometry knowledge. Numerical simulations were conducted to analyze the laws of pointing errors. The simulation results show that the bending deformation angle has a great influence on the azimuth pointing error and the parallel error of the two collimation axes. Then two experimental platforms were established to validate the theoretical analyses. The experimental results are consistent with the theoretical results, which prove the correctness of the theoretical derivation.

High Precision Position Measurement Method for Laguerre-Gaussian Beams Using a Quadrant Detector.

In this paper, we propose a new method to improve the position measurement accuracy for Laguerre-Gaussian beams on a quadrant detector (QD). First, the error effects of the detector diameter and the gap size are taken into account, and the position error compensation factor is introduced into the conventional formula. Then, in order to reduce the number of parameters, the concept of effective radius is proposed. Thus, a new analytical expression is obtained with a best fit using the least square method. It is verified by simulation that this approach can reduce the maximum error by 97.4% when the beam radius is 0.95 mm; meanwhile, the root mean square errors under different radii are all less than 0.004 mm. The results of simulation show that the new method could effectively improve the accuracy of the QD measurement for different radii. Therefore, the new method would have a good prospect in the engineering practice of beam position measurements.

Generation of coherent and incoherent Airy beam arrays and experimental comparisons of their scintillation characteristics in atmospheric turbulence.

We investigate, through numerical calculation and experiments, the incoherent combination of a 2D Airy beam array (ICCAB) and the coherent combination of a 2D Airy beam array (CCAB), respectively. Excellent experimental results are obtained for both ICCAB and CCAB. The on-axis scintillation indices of ICCAB and CCAB at the receiver plane in atmospheric turbulence are also compared experimentally. It is shown that ICCAB has a smaller scintillation index than that of CCAB in the same turbulent condition due to the coherence reduction of the constituent beamlets. The results obtained in this paper are useful for the development of beam propagation through atmosphere turbulence.

Performance improvement of coherent free-space optical communication with quadrature phase-shift keying modulation using digital phase estimation.

The performance of coherent free-space optical (CFSO) communication with phase modulation is limited by both phase fluctuations and intensity scintillations induced by atmospheric turbulence. To improve the system performance, one effective way is to use digital phase estimation. In this paper, a CFSO communication system with quadrature phase-shift keying modulation is studied. With consideration of the effects of log-normal amplitude fluctuations and Gauss phase fluctuations, a two-stage Mth power carrier phase estimation (CPE) scheme is proposed. The simulation results show that the phase noise can be suppressed greatly by this scheme, and the system symbol error rate performance with the two-stage Mth power CPE can be three orders lower than that of the single-stage Mth power CPE. Therefore, the two-stage CPE we proposed can contribute to the performance improvements of the CFSO communication system and has determinate guidance sense to its actual application.

Improved method to fully compensate the spatial phase nonuniformity of LCoS devices with a Fizeau interferometer.

Liquid crystal on silicon (LCoS) devices usually show spatial phase nonuniformity (SPNU) in applications of phase modulation, which comprises the phase retardance nonuniformity (PRNU) as a function of the applied voltage and inherent wavefront distortion (WFD) introduced by the device itself. We propose a multipoint calibration method utilizing a Fizeau interferometer to compensate SPNU of the device. Calibration of PRNU is realized by defining a grid of 3×6 cells onto the aperture and then calculating phase retardance of each cell versus a gradient gray pattern. With designing an adjusted gray pattern calculated by the calibrated multipoint phase retardance function, compensation of inherent WFD is achieved. The peak-to-valley (PV) value of the residual WFD compensated by the multipoint calibration method is significantly reduced from 2.5λ to 0.140λ, while the PV value of the residual WFD after global calibration is reduced to 0.364λ. Experimental results of the generated finite-energy 2D Airy beams in Fourier space demonstrate the effectiveness of this multipoint calibration method.

Improved measurement accuracy of spot position on an InGaAs quadrant detector.

In this paper, a new formula is proposed to improve the accuracy of spot position measurements on an InGaAs quadrant detector (QD). It is obtained by analyzing the relationship between the light spot position and the output signals of the QD and combining the infinite integral method with the Boltzmann method due to their opposite error characteristics. Based on the proposed formula, the measurement accuracy can be improved greatly, which is confirmed by the simulation and experimental results. In addition, it requires fewer parameters compared with the polynomial method when reaching the same accuracy. Thus, the new formula can be practical in applications of spot position measurements.

Antioxidant and anti-inflammatory effects of different ratios and preparations of Angelica sinensis and chuanxiong rhizoma extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: Angelica sinensis (AS) and Chuanxiong rhizoma (CR) are frequently prescribed in clinical settings for their ability to enrich blood, regulate menstrual cycles, and alleviate pain. Despite their widespread use, there is a relative dearth of studies exploring their anti-inflammatory properties. AIM OF THE STUDY: To evaluate the antioxidant and anti-inflammatory effects of Angelica sinensis-Chuanxiong rhizoma (ASCR) extracts and investigate its anti-inflammatory mechanisms. MATERIALS AND METHODS: AS and CR were combined in six ratios and extracted using five solvents. The quality of the resulting ASCR extracts was assessed by determining the content of ferulic acid (FA) using HPLC. The antioxidant effects of the ASCR extracts were evaluated in vitro using the DPPH and ABTS assays, as well as in HUVECs exposed to H2O2-induced oxidative damage. Additionally, the anti-inflammatory effects of the extracts were investigated in vivo through the assays of ear edema in mice and paw edema in rats. Biochemical markers including NO, MDA, and SOD in paw tissues, as well as PGE2, TNF-α, and COX-2 in rat serum, were measured to further elucidate the anti-inflammatory mechanisms of ASCR extracts. RESULTS: The WA-2-1 was obtained by combining AS and CR in a 2:1 ratio through first water then ethanol extraction, and showed favorable antioxidant and anti-inflammatory activities. The extract demonstrated effective scavenging abilities against DPPH• and ABTS+• radicals while also protecting against H2O2-induced oxidative damage. Furthermore, in vivo studies revealed that WA-2-1 had significant inhibitory effects on ear and paw edema as well as the ability to decrease NO and MDA levels, enhance SOD activity, and downregulate the expression of COX-2, PGE2, and TNF-α. CONCLUSIONS: The combination of AS and CR exhibits favorable anti-inflammatory effects, attributed to its dual actions of mitigating oxidative stress and suppressing the production of inflammatory mediators in serum or tissues during the inflammatory process.

Metal-organic framework-mediated siRNA delivery and sonodynamic therapy for precisely triggering ferroptosis and augmenting ICD in osteosarcoma.

The complex genomics, immunosuppressive tumor microenvironment (TME), and chemotherapeutic resistance of osteosarcoma (OS) have resulted in limited therapeutic effects in the clinic. Ferroptosis is involved in tumor progression and is regulated mainly by glutathione peroxidase 4 (GPX4). Small interfering RNA (siRNA)-based RNA interference (RNAi) can precisely target any gene. However, achieving effective siRNA delivery is highly challenging. Here, we fabricated a TME-responsive metal-organic framework (MOF)-based biomimetic nanosystem (mFeP@si) with siGPX4 delivery and sonodynamic therapy (SDT) to treat OS by targeting ferroptosis. Under ultrasound (US) irradiation, mFeP@si achieves lysosomal escape via singlet oxygen (1O2)-mediated lysosomal membrane disruption and then accelerates ROS generation and glutathione (GSH) depletion. Meanwhile, siGPX4 silences GPX4 expression by binding to GPX4 mRNA and leads to the accumulation of toxic phospholipid hydroperoxides (PL-OOH), further magnifying the ROS storm and triggering ferroptosis. Notably, synergistic therapy remarkably enhances antitumor effects, improves the immunosuppressive TME by inducing potent immunogenic cell death (ICD), and increases the sensitivity of chemotherapy-resistant OS cells to cisplatin. Overall, this novel nanosystem, which targets ferroptosis by integrating RNAi and SDT, exhibits strong antitumor effects both in vitro and in vivo, providing new insights for treating OS.

Systematical construction of rice flavor types based on HS-SPME-GC-MS and sensory evaluation.

Rice is one of the main staple foods of Chinese people and its quality requirements are also improving. Aroma is one of the evaluation factors of rice quality, rice with better aroma quality is often more accepted by consumers. A universal aroma descriptive lexicon was established and four flavor types were formed based on samples from 9 representative rice cultivation regions. The key variables affecting the sensory quality of Chinese rice flavor were screened. It was found that the hexanal and nonanal with the highest content had no effect on the flavor properties, which suggests that volatile organic compounds (VOCs) content is not necessarily related to the influence of flavor properties. According to the aroma analysis of different rice flavor types, it can provide guidance for other flavor research.

Defective SO3H-MIL-101(Cr) for capturing different cationic metal ions: Performances and mechanisms.

For broad-spectrum adsorption and capture toward cationic metal ions, a facile strategy was adopted to fabricate defective SO3H-MIL-101(Cr) (SS-SO3H-MIL-101(Cr)-X, X = 2, 3, 4) with enhanced vacancies using seignette salt (SS) as the modulating agent. The boosted adsorption performances of SS-SO3H-MIL-101(Cr)-X toward eight different ions, including Ag+, Cs+, Pb2+, Cd2+, Ba2+, Sr2+, Eu3+ and La3+ in both individual component and mixed component systems, could be ascribed to the effective mass transfer resulting from the exposure of defective sites. Especially, the optimal SS-SO3H-MIL-101(Cr)-3 could remove all the selected metal cations to below the permissible limits required by the World Health Organization (WHO) in the continuous-flow water treatment system. Furthermore, SS-SO3H-MIL-101(Cr)-3 exhibited good adsorption capacity (189.6 mg·g-1) toward Pb2+ under neutral condition and excellent desorption recirculation performance (removal efficiency > 95% after 5 cycles). Moreover, the adsorption mechanism involved the electrostatic adsorption and coordinative interactions resulting from complexation between the adsorption active sites and targeted cations (like Cr-O-M and S-O-M), which were explored systematically via both X-ray photoelectron spectroscopy (XPS) determination and density functional theory (DFT) calculations. Overall, this work provided guidance for modulating SS-SO3H-MIL-101(Cr)-X to promote its potential application in widespread metal cations removal from wastewater.

Research progress on nanomaterial-based matrices for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis.

Matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a novel soft ionization bio-mass spectrometry technology emerging in the 1980s, which can realize rapid detection of non-volatile, highly polar, and thermally unstable macromolecules. However, the analysis of small molecular compounds has been a major problem for MALDI-TOF MS all the time. In the MALDI analysis process based on traditional matrices, large numbers of interference peaks in the low molecular weight area and "sweet spots" phenomenon are produced, so the detection method needs to be further optimized. The promotion of matrix means the improvement of MALDI performance. In recent years, many new nanomaterial-based matrices have been successfully applied to the analysis of small molecular compounds, which makes MALDI applicable to a wider range of detection and useful in more fields such as pharmacy and environmental science. In this paper, the newly developed MALDI matrix categories in recent years are reviewed initially. Meanwhile, the potential applications, advantages and disadvantages of various matrices are analyzed. Finally, the future development prospects of nanomaterial-based matrices are also prospected.