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Ultrasound (US) shear wave (SW) elastography has been widely studied and implemented on clinical systems to assess the elasticity of living organs. Imaging of SW attenuation reflecting viscous properties of tissues has received less attention. A revisited frequency shift (R-FS) method is proposed to improve the robustness of SW attenuation imaging. Performances are compared with the FS method that we originally proposed and with the two-point frequency shift (2P-FS) and attenuation measuring US SW elastography (AMUSE) methods. In the proposed R-FS method, the shape parameter of the gamma distribution fitting SW spectra is assumed to vary with distance, in contrast to FS. Second, an adaptive random sample consensus (A-RANSAC) line fitting method is used to prevent outlier attenuation values in the presence of noise. Validation was made on ten simulated phantoms with two viscosities (0.5 and 2 Pa [Formula: see text]) and different noise levels (15 to -5 dB), two experimental homogeneous gel phantoms, and six in vivo liver acquisitions on awake ducks (including three normal and three fatty duck livers). According to the conducted experiments, R-FS revealed mean reductions in coefficients of variation (CV) of 62.6% on simulations, 62.5% with phantoms, and 62.3% in vivo compared with FS. Corresponding reductions compared with 2P-FS were 45.4%, 77.1%, and 62.0%, respectively. Reductions in normalized root-mean-square errors for simulations were 63.9% and 48.7% with respect to FS and 2P-FS, respectively.

Shear wave elastography (speed and dispersion), local attenuation coefficient slope and homodyned-K parametric imaging were used for liver steatosis grading. These ultrasound biomarkers rely on physical interactions between shear and compression waves with tissues at both macroscopic and microscopic scales. These techniques were applied in a context not yet studied with ultrasound imaging, that is, monitoring steatosis of force-fed duck livers from pre-force-fed to foie gras stages. Each estimated feature presented a statistically significant trend along the feeding process (p values

It is known that changes in the mechanical properties of tissues are associated with the onset and progression of certain diseases. Ultrasound elastography is a technique to characterize tissue stiffness using ultrasound imaging either by measuring tissue strain using quasi-static elastography or natural organ pulsation elastography, or by tracing a propagated shear wave induced by a source or a natural vibration using dynamic elastography. In recent years, deep learning has begun to emerge in ultrasound elastography research. In this review, several common deep learning frameworks in the computer vision community, such as multilayered perceptron, convolutional neural network, and recurrent neural network, are described. Then, recent advances in ultrasound elastography using such deep learning techniques are revisited in terms of algorithm development and clinical diagnosis. Finally, the current challenges and future developments of deep learning in ultrasound elastography are prospected.

Change in viscoelastic properties of biological tissues may often be symptomatic of dysfunction that can be correlated with tissue pathology. Shear wave (SW) elastography is an imaging method mainly used to assess stiffness but with the potential to measure viscoelasticity of biological tissues. This can enable tissue characterization and, thus, can be used as a marker to improve the diagnosis of pathological lesions. In this study, a frequency-shift method-based framework is presented for the reconstruction of viscosity by analyzing the spectral properties of acoustic radiation force-induced SWs. The aim of this study was to investigate the feasibility of viscosity reconstruction maps in homogeneous as well as heterogeneous samples. Experiments were performed in four in vitro phantoms, two ex vivo porcine liver samples, two ex vivo fatty duck liver samples, and one in vivo fatty goose liver. Successful viscosity maps were reconstructed in homogeneous and heterogeneous phantoms with embedded mechanical inclusions having different geometries. Quantitative values of viscosity obtained for two porcine liver tissues, two fatty duck liver samples, and one goose fatty liver were (mean ± SD) 0.61 ± 0.21 and 0.52 ± 0.35, 1.28 ± 0.54 and 1.36 ± 0.73, and 1.67 ± 0.70 Pa.s, respectively.

Elastic changes in cells indicate their functional, anatomical, and pathological states as the cytoskeleton network reorganizes. In the first section, a cursory introduction of the cellular architecture that influences the elastic properties of cells is provided. Following this, the clinical implications of elasticity changes to the cell phenotype and consequently its pathophysiology is discussed. The second section provides a basic introduction on technologies used to assess cell elasticity. This section discusses measurement techniques in the context of the critical spatio-temporal resolution necessary to capture dynamic cellular processes and the phenotype of subcellular structures. Choosing the right mechanical model has been suggested as a key milestone in developing a robust method for single-cell elastography. Consequently, a section on the necessity and considerations in rheological modeling of single cells is included in the third section. To conclude the chapter, an overview of miscellaneous approaches with the potential to extract both the elastic and viscous properties of cells, model-independent imaging methods, and adaptation of techniques for high-throughput imaging are presented.

Ultrasound shear wave elastography and assessment of attenuation can increase the diagnostic accuracy of numerous diseases. The main objective of this work was to propose two improvements to the frequency shift (FS) method for shear wave attenuation assessment. First, the shape parameter of the gamma distribution employed to fit the spectrum amplitude of shear waves now varies spatially. Second, a random sample consensus (RANSAC) line fitting method is utilized for calculating the attenuation due to its superiority in the presence of noise and outliers. The shear wave propagation in a tissue-mimicking numerical phantom was modeled as a Kelvin-Voigt (KV) viscoelastic material with finite element (FE) simulations in COMSOL. The shear wave amplitude spectrum was fit using a gamma distribution function, and the slope of the rate parameter of this function obtained by the RANSAC method provided the attenuation coefficient. This method was applied to two numerical phantoms (viscosity of 0.5 and 2 Pa.s), two experimental tissue-mimicking viscoelastic phantoms, and two ex vivo blood clot samples embedded in phantoms. Numerical phantoms were also investigated in the presence of Gaussian random noise at SNR levels of 20 dB to 0 dB. Results were compared with FS, two-point frequency shift (2P-FS) method, and attenuation measuring ultrasound shear wave elastography (AMUSE) method. Mean values of the attenuation coefficient, averaged over a region of interest, were compared between implemented methods. For simulations at different SNRs, the proposed, 2P-FS and AMUSE methods gave mean values close to the KV model. At a SNR of 0 dB, biases of the proposed method were 0.0025 and 0.0258 Np/m/Hz, and variances were 0.0024 and 0.0158 (Np/m/Hz)2, for viscosities of 0.5 and 2 Pa.s, respectively. For homogeneous gel phantoms, mean values of the proposed method were: #1) 0.4351; #2) 0.4621. For blood clot phantoms, mean values were: #1) 0.2573; #2) 0.9875. Biases of the proposed method compared to KV or AMUSE were smaller for numerical phantoms, whereas its variance was less than 2P-FS for all datasets.

Deep neural networks have demonstrated potential to both create images and segment structures of interest directly from raw ultrasound data in one step, through an end-to-end transformation. Building on previous work from our group, subaperture beamformed IQ data from in vivo breast cyst data was the input to a custom network that outputs parallel B-mode and cyst segmentation images. Our new model includes bright point and line targets during training to overcome the limited field of view challenges encountered with our previous deep learning models, which were purely trained using simulations of cysts and homogeneous tissue structures. This new network resulted in cyst contrast values of $-33.07\pm 10.79\ \text{dB}, -32.09\pm 0.04 \text{dB}$ , and $-15.95\pm 12.04\ \text{dB}$ for simulated, phantom, and in vivo data, respectively, which is an improvement over the contrast of corresponding delay and sum (DAS) images (i.e., $-17.37\pm 6.06\ \text{dB},\ -17.14\pm 0.16\ \text{dB}$ , and $14.80\pm 1.30\ \text{dB}$ for simulated, phantom, and in vivo, respectively). Higher dice similarity coefficients (DSCs) were obtained with in vivo data with the new network ( .83 \pm 0.01$ ) when compared to our previous model ( .63\pm 0.03$ ), and fewer false positives were encountered. This work demonstrates the feasibility of using multi-task learning to simultaneously form a B-mode image and cyst segmentation with a wider field of view that is appropriate for in vivo breast imaging. These results have promising implications for multiple tasks, including emphasizing or de-emphasizing structures of interest for diagnostic, interventional, automated, and semi-automated decision making.

Piezoelectric-related multiproperty coupling effects have recently attracted much attention for developing next generation multifunctional devices. In this paper, the multiproperty coupling effects...

Level of evidence: Not applicable for this multicentre audit

Multi-parametric ultrasound imaging is a promising tool for quantification of nonalcoholic fatty liver disease. In this work, a protocol of plane wave quantitative ultrasound (QUS) and shear wave elastography imaging (SWEI), quasi-simultaneously acquired, and dedicated to the quantification of liver steatosis on in vivo fatty duck livers is presented. Shear wave velocity was estimated to classify stiffness in duck liver tissues. QUS consisted in the local attenuation coefficient slope estimated with the spectral log difference method, and coherent-to-diffuse signal ratio computed from homodyned-K parametric maps. SWEI revealed a constant increase of the liver stiffness over the 16-days feeding process. After 9 days of feeding, ultrasound attenuation reached a maximum and the coherent-to-diffuse signal ratio reached a minimum. Coupled together, SWEI and QUS promise a strong potential for steatosis monitoring of fatty liver tissues, in ducks or humans.

Changes in viscoelastic properties of biological tissues may be symptomatic of a dysfunction that can be correlated to tissue pathology. Past magnetic resonance imaging studies suggest that tumors have higher viscosity than normal tissues, and fatty organs might also correlate with higher viscosity. In this study, a frequency-shift method to compute attenuation was utilized to reconstruct viscosity maps by analyzing spectral properties of induced shear waves. The feasibility of viscosity reconstructions in animal tissue samples is investigated. Experiments were performed in an in vitro phantom, as well as in ex vivo and in vivo animal tissue samples of healthy and fatty livers. Quantitative values of viscosity obtained for two porcine liver tissues, two fatty duck liver samples, and one goose fatty liver imaged in vivo are 0.61 ± 0.21, 0.52 ± 0.35; 1.28 ± 0.54, 1.36 ± 0.73, and 1.67 ± 0.70 Pa.s, respectively.

INTRODUCTION: Cesarean section is a live saving procedure but when performed without appropriate indications can add risk to both mother and baby. As per WHO report, at population level, Cesarean section rates higher than 10% are not associated with reductions in maternal and new-born mortality rates. In India as per District level household survey 3 (DLHS) Cesarean section rate is 28.1% in private sector and 12% in public sector health care facilities. The close embryonic development and anatomical proximity of the urinary bladder and genital organs, are responsible for the urinary tract to injury during surgical procedures in the female pelvis. During LSCS bladder injury is demonstrated by the presence of gas filling up the Foley bag or visibly bloody urine in the Foley bag. Veress needle injuries and other small injuries to the bladder can be successfully managed conservatively by catheter drainage for seven to 14 days followed by cystography while large bladder injuries, such as from 5 or 10 mm trocar or surgical dissection usually require suturing the injuries closed. Risk factors for bladder injury during LSCS include previous operations, expodure to radiation, malignancy, chronic infection, and inflammation. MATERIAL AND METHODS: In suspected cases of bladder injuries cystogram X-ray of the bladder after injection of contrast medium is performed. For extraperitoneal injuries (grade 2) without complicating factors, treatment is a insertion of Foley catheter for 7 - 14 days. grade 3 to grade 5 injuries generally require operative repair. Closed suction drains should be left in place after repairs. Suprapubic tube placement is not necessary in most cases. For injuries to the ventral bladder, dome, or posterior bladder, the mucosa is closed in a running fashion using 3-0 vicryl followed by a seromuscular running suture of 2-0 vicryl. The bladder is irrigated to ensure a watertight closure. A third layer in a Lembert fashion can be used in cases at high risk for fistula formation or when a leak is identified. In the laparoscopic setting, a one-layer closure is performed using 2-0 vicryl to close all layers of the bladder. An additional layer can then be added using a 2- 0 vicryl in a Lembert fashion for more extensive injuries. RESULTS: There were 986 LSCS done in the department of Obstetrics and gynaecology in the given study period. Of which 14 were diagnosed with the bladder injuries during. Among all patients who suffered from bladder injury, 3 cases were primigravida and 11 were multigravida type. Out of 14injuries, 10 injuries were repaired in 2 layers by vicryl 2.0 without insertion of SPC (suprapubic cystectomy) whereas 4 injuries were repaired by primary repair with vicryl 2.0 with insertion of SPC. In post-operative period patients were monitored for vitals, urine output and stitch sites of wounds. No complications were found in 13 patients post operatively and Foleys catheter and SPC catheter were removed after 12 days of operation in those patients. CONCLUSION: 1.4% of the bladder injuries were observed. Early detection and prompt management of bladder injury can decrease the morbidity and mortality in LSCS cases

INTRODUCTION: Lower Segment Cesarean Section (LSCS) delivery is a major obstetrical surgical procedure to save the lives of mothers and fetus. Various risk factors in SSI following LSCS has been identified which includes subcutaneous hematoma, subcutaneous hematoma, tobacco use in pregnancy, incision length > 16.6 cm , body mass index >30 or 35 kg/m2, prolonged second stage (compared with first stage) , no antibiotic prophylaxis, duration of labor >12 h , premature rupture of membranes , gestational diabetes, previous cesarean delivery and emergency delivery. Diagnosis of surgical site infection requires evidence of clinical signs and symptoms of infection which may be further supported by microbiological evidence. MATERIAL AND METHODS: A total of 646 patients were included in the study of which 27 were diagnosed as SSI. Risk factor for SSI was divided into three categories: 1) host-related factors, 2) pregnancy and intrapartum-related factors, and 3) procedure-related factors. RESULTS: Among 646 cesarean sections, surgical site infection was observed in 27(4.1%) cases while he remaining cases had no surgical site infection. Mean age of cases with surgical site infection was observed to be 14.8 years with sd of 3.9 years where as it was 22.1 years in cases with no surgical site infections and sd of 3.2 years. Average number of stay in hospital is found to be 14.1 and 7.3 days respectively in cases with and without surgical site infections. Antibiotics were given on 17.3 days on average in cases with SSI whereas patients without surgical site infections were on antibiotics for 3.1 days on average. Out of total 27 surgical site infection E-coli was isolated in 11(40.8%) cases followed by 7(25.9%) isolations of staphylococcus aureus. Klebsiella pneumonia and pseudomonas aeruginosa were isolated in 3(11.1%) cases each. Acitenobacter was found in only 1(3.7%) case. 2(7.4%) isolates were not identified in our study. CONCLUSION: To reduce the SSI rates post LSCS, proper assessment of risk factors and their modification is required. Frequent antibiotic susceptibility testing for resistance is required.

We proposed a deterministic Rabin cryptosystem algorithm for encryption and decryption. It is based on converting non deterministic Rabin cryptosystem to deterministic Rabin cryptosystem without Jacobi symbol. A message based on redundant technique or padding bits are used to distinguish the original message from the other messages. There is a need to maintain redundancy in the message, such that decrypted message is specific except for the task having very less probability. The proposed scheme works well for a variable odd length plain text messages.

Deep vein thrombosis is one of the leading causes of disability and serious illness and can become fatal. The lytic recombinant tissue plasminogen activator (rt-PA) is the main drug used for clot lysis and rapid normalization of venous blood flow. Less than 40% of patients who receive rt-PA treatment have improved blood flow. In this study, we quantitatively monitor the rt-PA treatment in in-vitro blood clots with ultrasound elastography. An acoustic radiation force imaging sequence was implemented on a research ultrasound system to remotely generate shear waves inside the blood clot samples. Porcine blood samples from two different pigs were bought from a local slaughterhouse. Clots of varying viscoelasticity were prepared by allowing different coagulation time between 30 min to 3 days in borosilicate glass pipettes. The clots were then embedded in gelatin-agar phantoms to perform ultrasound measurements. Another batch of clots from the same blood samples was treated with rt-PA drug for 30 min, and ultrasound measurements were performed after treatment. In 11 samples, variations in SW speed before and after rt-PA treatment were not found to be statistically significant (>0.05). However, SW attenuation and clot viscosity declined significantly after rt-PA treatment by 33.49% ± 31.07% (

The limited data photoacoustic image reconstruction problem is typically solved using either weighted or ordinary least squares (LS), with regularization term being added for stability, which account only for data imperfections (noise). Numerical modeling of acoustic wave propagation requires discretization of imaging region and is typically developed based on many assumptions, such as speed of sound being constant in the tissue, making it imperfect. In this work, two variants of total least squares (TLS), namely ordinary TLS and Sparse TLS were developed, which account for model imperfections. The ordinary TLS is implemented in the Lanczos bidiagonalization framework to make it computationally efficient. The Sparse TLS utilizes the total variation penalty to promote recovery of high frequency components in the reconstructed image. The Lanczos truncated TLS (Lanczos T-TLS) and Sparse TLS methods were compared with the recently established state-of-the-art methods, such as Lanczos Tikhonov and Exponential Filtering. The TLS methods exhibited better performance for experimental data as well as in cases where modeling errors were present, such as few acoustic detectors malfunctioning and speed of sound variations. Also, the TLS methods does not require any prior information about the errors present in the model or data, making it attractive for real-time scenarios. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) NMRC (Natl Medical Research Council, S’pore) MOH (Min. of Health, S’pore) Accepted version

The model-based image reconstruction techniques for photoacoustic (PA) tomography require an explicit regularization. An error estimate (η2) minimization-based approach was proposed and developed for the determination of a regularization parameter for PA imaging. The regularization was used within Lanczos bidiagonalization framework, which provides the advantage of dimensionality reduction for a large system of equations. It was shown that the proposed method is computationally faster than the state-of-the-art techniques and provides similar performance in terms of quantitative accuracy in reconstructed images. It was also shown that the error estimate (η2) can also be utilized in determining a suitable regularization parameter for other popular techniques such as Tikhonov, exponential, and nonsmooth (l1 and total variation norm based) regularization methods.

The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer–Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer–Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.

Deep vein thrombosis is a common vascular disease that can lead to pulmonary embolism and death. The early diagnosis and clot age staging are important parameters for reliable therapy planning. This article presents an acoustic radiation force induced resonance elastography method for the viscoelastic characterization of clotting blood. The physical concept of this method relies on the mechanical resonance of the blood clot occurring at specific frequencies. Resonances are induced by focusing ultrasound beams inside the sample under investigation. Coupled to an analytical model of wave scattering, the ability of the proposed method to characterize the viscoelasticity of a mimicked venous thrombosis in the acute phase is demonstrated. Experiments with a gelatin-agar inclusion sample of known viscoelasticity are performed for validation and establishment of the proof of concept. In addition, an inversion method is applied in-vitro for the kinetic monitoring of the blood coagulation process of six human blood samples obtained from two volunteers. The computed elasticity and viscosity values of blood samples at the end of the 90 min kinetics were estimated at 411 ± 71 Pa and 0.25 ± 0.03 Pa.s for volunteer #1, and 387 ± 35 Pa and 0.23 ± 0.02 Pa.s for volunteer #2, respectively. The proposed method allowed reproducible time-varying thrombus viscoelastic measurements from samples having physiological dimensions.

A high-performance broad band UV/visible photodetector has been successfully fabricated on a fully wide bandgap ZnO/ZnS type-II heterojunction core/shell nanowire array. The device can detect photons with energies significantly smaller (2.2 eV) than the band gap of ZnO (3.2 eV) and ZnS (3.7 eV), which is mainly attributed to spatially indirect type-II transition facilitated by the abrupt interface between the ZnO core and ZnS shell. The performance of the device was further enhanced through the piezo-phototronic effect induced lowering of the barrier height to allow charge carrier transport across the ZnO/ZnS interface, resulting in three orders of relative responsivity change measured at three different excitation wavelengths (385, 465, and 520 nm). This work demonstrates a prototype UV/visible photodetector based on the truly wide band gap semiconducting 3D core/shell nanowire array with enhanced performance through the piezo-phototronic effect.

Undersea deposition of unexploded ordnance (UXO) constitutes a potential source of contamination of marine environments by hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). Using sediment from a coastal UXO field, Oahu Island, Hawaii, we isolated four novel aerobic RDX-degrading fungi HAW-OCF1, HAW-OCF2, HAW-OCF3 and HAW-OCF5, tentatively identified as members of Rhodotorula, Bullera, Acremonium and Penicillium, respectively. The four isolates mineralized 15-34% of RDX in 58 days as determined by liberated 14CO2. Subsequently we selected Acremonium to determine biotransformation pathway(s) of RDX in more details. When RDX (100 microM) was incubated with resting cells of Acremonium we detected methylenedinitramine (MEDINA), N2O and HCHO. Also we detected hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) together with trace amounts of hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX) and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX). Under the same conditions MNX produced N2O and HCHO together with trace amounts of DNX and TNX, but we were unable to detect MEDINA. TNX did not degrade with Acremonium. These experimental findings suggested that RDX degraded via at least two major initial routes; one route involved direct ring cleavage to MEDINA and another involved reduction to MNX prior to ring cleavage. Nitrite was only detected in trace amounts suggesting that degradation via initial denitration did take place but not significantly. Aerobic incubation of Acremonium in sediment contaminated with RDX led to enhanced removal of the nitramine.

Undersea deposition of unexploded ordnance (UXO) constitutes a potential source of contamination of marine environments by hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The goal of the present study was to determine microbial degradation of RDX and HMX in a tropical marine sediment sampled from a coastal UXO field in the region of Oahu Island in Hawaii. Sediment mixed cultures growing in marine broth 2216 (21 degrees C) anaerobically mineralized 69% or 57% (CO2, 25 days) of the total carbon of [UL-14 C]-RDX (100 microM) or [UL-14 C]-HMX (10 microM), respectively. As detected by PCR-DGGE, members of gamma-proteobacteria (Halomonas), sulfate-reducing delta-proteobacteria (Desulfovibrio), firmicutes (Clostridium), and fusobacterium appeared to be dominant in RDX-enrichment and/or HMX-enrichment cultures. Among 22 sediment bacterial isolates screened for RDX and HMX biodegradation activity under anaerobic conditions, 5 were positive for RDX and identified as Halomonas (HAW-OC4), Marinobacter (HAW-OC1), Pseudoalteromonas (HAW-OC2 and OC5) and Bacillus (HAW-OC6) by their 16S rRNA genes. Sediment bacteria degraded RDX to N2O and HCHO via the intermediary formation of hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and methylenedinitramine. The present findings demonstrate that cyclic nitramine contaminants are likely to be degraded upon release from UXO into tropical marine sediment.

Obstetric anesthesia is demanding but gratifying subspeciality of anesthesiologist. Anesthetic care of pregnant patient is unique in that two patients are cared for simultaneously; the parturient and the foetus. This study was conducted on 50 parturient of ASA I and ASA II, planed for caesarean section. They were randomly divided into two groups of 25 patients each: Group-A (control) 1.8cc bupivacaine 0.5% + 0.5 cc normal saline. Total 2.3cc and Group-B (study) 1.8cc bupivacaine 0.5% +25 mg ketamine 0.5 cc (preservative free) Total 2.3 cc. We summarized that intrathecal 0.5% bupivacaine with preservative free intrathecal ketamine have rapid onset of sensory block, have better hemodynamic stability and have post operative analgesia without affecting neonate. Thus it is safe modality for the parturient undergoing caesarean section, but central side effects like delirium, nystagmus and sedation can occur in some patients.

Groundwater (GW) from the Bitterfeld industrial region, Central Germany, is contaminated mainly with monochlorobenzene (MCB). Accordingly, current research addresses the development of feasible in situ groundwater remediation technologies. Although easily degradable under aerobic conditions, MCB persists in the essentially anaerobic Bitterfeld aquifer. Therefore, we focused on primary oxidation of MCB and the subsequent anaerobic biodegradability of MCB oxidation products by the indigenous microbial community. In groundwater microcosms, most efficient MCB removal was observed upon treatment with Fenton’s reagent (H2O2 + Fe2+), which produces the highly reactive hydroxyl radical and Fe3+ simultaneously. Phospholipid fatty acid analysis following different treatments suggested respective shifts of the microbial community compositions, and indicated that Fenton’s reagent had a rather beneficial than an adverse effect on biomass development. Potential metabolites of hydroxyl radical attack on MCB such as chlorohydroquinone, hydroquinone, catechol, resorcinol, and phenol were anaerobically degraded by the groundwater microbial community under Fe3+-reducing conditions.

Much of the intervention research for prevention of occupational low back injuries has focused on reduction of torso flexion and the external moment. Little is known about prevention strategies for torso twisting and lateral bending. It was hypothesized that increasing the distance between the lift origin and the pallet would require subjects to take an extra step, and reduce the torso kinematics and resulting LBD Risk. Fifteen males transferred 11.3 kg boxes from a constant origin to a destination pallet at two different distances. Analysis of Variance results indicated that increasing the pallet distance from the lift origin resulted in increases in velocities and accelerations, and the LBD risk at the lower regions of the pallet. These results suggest that increasing the pallet distance from the lifting origin does not appear to be an effective intervention strategy to reduce the risk of occupational LBD associated with torso kinematics.

To advance the photodetection capabilities of type II core/shell nanowire-based photodetectors, ZnSe has been employed to coat on ZnO nanowire array creating a type-II heterojunction core/shell nanowire array with additional lower indirect band gap (≈1.84 eV), via a facile two-step process of chemical vapor deposition and pulse laser ablation. The integrated photodetector based on the ZnO/ZnSe core/shell structure is capable of detecting the entire range of the visible spectrum, from blue to red excitation source, as well as UV light. The absolute sensitivity and the percentage change in responsivity of the photodetector are enhanced by one and three orders of magnitude, respectively. The whole range visible light photodetection and enhanced photocurrent response are attributed to the unique ZnO/ZnSe energy band realignment and the piezophototronic effect. Moreover, the photodetector exhibits self-powered photodetection behavior under UV/visible light illumination. This study grants a potential application using ZnO/ZnSe type II heterostructure core/shell nanowire array for broad band UV/visible photodetection in both powered and self-powered circumstances.

Model-based image reconstruction techniques yield better quantitative accuracy in photoacoustic image reconstruction. In this work, an exponential filtering of singular values was proposed for carrying out the image reconstruction in photoacoustic tomography. The results were compared with widely popular Tikhonov regularization, time reversal, and the state of the art least-squares QR-based reconstruction algorithms for three digital phantom cases with varying signal-to-noise ratios of data. It was shown that exponential filtering provides superior photoacoustic images of better quantitative accuracy. Moreover, the proposed filtering approach was observed to be less biased toward the regularization parameter and did not come with any additional computational burden as it was implemented within the Tikhonov filtering framework. It was also shown that the standard Tikhonov filtering becomes an approximation to the proposed exponential filtering.

Intervention research for prevention of occupational low back injuries has focused on the effects of reducing extreme torso flexion and the external moment. Little is known about prevention strategies for torso twisting and lateral bending. The objective of this study was to assess the effect of pallet distance with regard to a constant lift origin on the torso kinematics and a measure of low back disorder risk. Fifteen male participants transferred 11.3 kg boxes from a constant origin to six different regions on a pallet. Two pallet distances with regard to the lift origin were investigated. ANOVA indicated that increasing the pallet distance resulted in increases in torso kinematics (velocities and accelerations) as well as a measure of risk of low back disorder. The increases in torso kinematics (e.g. twisting and lateral awkward postures and bending velocities) occurred mostly at the lower height regions on the pallet. It is concluded that increasing the pallet distance with regard to the lifting origin, with the intention to influence the participant to take a step during a palletizing task does not appear to be an effective intervention strategy to reduce the risk of low back disorder associated with torso kinematics.