Responses of soil phosphorus cycling and bioavailability to plant invasion in river-lake ecotones.

The invasion of exotic plants in the river-lake ecotone has seriously affected the nutrient cycling processes in wetland soil. The South American species Alternanthera philoxeroides (Mart.) Griseb. is rapidly invading the river-lake ecotone in subtropical China, and has become the dominant species in the river-lake ecotone. However, there have been few studies on the effects of A. philoxeroides invasion on soil phosphorus (P) cycling and bioavailability in this ecotone. Here, we measured the bioavailable P fractions, physicochemical properties and nutrient content in the surface soils of the native plant (Zizania latifolia (Griseb.) Turcz and Nelumbo nucifera Gaertn.) communities and the adjacent invasive A. philoxeroides communities in three river-lake ecotones with different nutrient substrates in the subtropical Dongting Lake basin over a 3-year period to reveal the effects of A. philoxeroides invasion on the morphology and concentrations of soil bioavailable P. The principal coordinate analysis results showed that the A. philoxeroides invasion significantly altered the bioavailable P concentrations in the soil of native plant communities in the different river-lake ecotones, and this effect was not disturbed by the heterogeneity of the soil matrix. However, the effects of invasion into different native plant communities on the fractions of soil bioavailable P were different. Compared with native Z. latifolia and N. nucifera communities, A. philoxeroides invasion increased the concentration of inorganic P by 39.5% and 3.7%, respectively, and the concentration of organic P decreased by 32.7% and 31.9%, respectively. In addition, the invasion promoted P cycling and accumulation in the river-lake ecotone, which resulted in average decreases in the soil N:P and C:P ratios of 7.9% and 12.5%, respectively. These results highlight the impact of exotic plant invasions on nutrient cycling in wetland ecosystems in the river-lake ecotone, and this process may be detrimental to the late recovery of native plants.

Neural correlates of central pain sensitization in chronic low back pain: a resting-state fMRI study.

PURPOSE: The objective of this study is to explore the neural correlates of pain sensitization in patients with chronic low back pain (cLBP). While the association between cLBP and pain sensitization has been widely reported, the underlying brain mechanism responsible for this relationship requires further investigation. METHODS: Our study included 56 cLBP patients and 56 healthy controls (HC). Functional magnetic resonance imaging data were obtained, and the voxel-wise amplitude of low-frequency fluctuation (ALFF) was calculated to identify brain alterations in cLBP patients compared to HC groups. Pearson correlation coefficients were computed to explore the association between clinical data and brain alterations. Furthermore, mediation analyses were performed to investigate the path association between brain alterations and pain-related behaviors. RESULTS: Our findings revealed that patients with cLBP exhibited higher sensitivity, attention, and catastrophizing tendencies towards pain compared to HC. Furthermore, cLBP patients displayed significantly higher ALFF in various brain regions within the "pain matrix" and the default mode network when compared to HC. The altered precuneus ALFF was positively correlated with pain intensity (R = 0.51, P<0.001) and was negatively correlated with pain sensitivity (R = -0.43, P<0.001) in cLBP patients. Importantly, the effect of altered precuneus ALFF on pain intensity was mediated by pain threshold in these patients. CONCLUSION: Our study suggests that altered neural activity in the precuneus may contribute to pain hypersensitivity, which further exacerbating pain in cLBP patients.

T2 MRI at 3T of cartilage and menisci in patients with hyperuricemia: initial findings.

OBJECTIVE: To compare and evaluate T2 values of compartmental femorotibial cartilage and subregional menisci in patients with hyperuricemia at 3T. MATERIALS AND METHODS: Thirty-two subjects were included in this study and subdivided into two subgroups: 15 healthy controls (3 females, 12 males; mean age = 45.3 ± 10.9 years), 17 patients with hyperuricemia (2 females, 15 males; mean age = 44.4 ± 12.7 years). All subjects were assessed on a 3T MR scanner using an 8-channel phased-array knee coil (transmit-receive). Wilcoxon rank sum test and analysis of covariance (ANCOVA) were performed to determine whether there were any statistically significant differences in T2 values of compartmental femorotibial cartilage and subregional menisci between the two subgroups. RESULTS: Lateral tibial cartilage (48.6 ± 3.5 ms) in healthy subgroup had significantly lower (p < 0.05) T2 values than all subcompartments of femorotibial cartilage in hyperuricemia subgroup. Medial tibial cartilage (56.5 ± 4.3 ms) in hyperuricemia subgroup had significantly higher (p < 0.05) T2 values than all subcompartments of femorotibial cartilage except medial tibial cartilage in healthy subgroup. Medial anterior horn of meniscus (39.4 ± 2.9 ms) in healthy subgroup had significantly lower (p < 0.05) T2 values than all subregional menisci except both medial anterior horn and medial body segment of meniscus in hyperuricemia subgroup. CONCLUSION: T2 values in certain compartmental femorotibial cartilage and subregional menisci in patients with hyperuricemia are evidently and abnormally heightened compared with those in healthy subjects, to which special attention should be paid when diagnosing and treating the patients with hyperuricemia in the clinical setting. The LT cartilage had significantly lower T2 values (48.6 ± 3.5 ms) in healthy subgroup compared to all compartmental femorotibial cartilage in cohort with HU. MF cartilage had significantly lower T2 values (51.6 ± 2.9 ms) in healthy subgroup compared to both LF (54.4 ± 4.1 ms) and MT (56.5 ± 4.3 ms) in cohort with HU. MT cartilage had significantly higher T2 values (56.5 ± 4.3 ms) in cohort with HU subgroup compared to LF (52.5 ± 3.0 ms) in healthy subgroup. T2 mapping may be promising and potential sensitive discriminator of understanding and examining the early compositional and structural change in proteoglycan-collagen matrix of human femorotibial cartilage in patients with hyperuricemia.

Effects of a spatially heterogeneous nutrient distribution on the growth of clonal wetland plants.

BACKGROUND: Clonal plants are important in maintaining wetland ecosystems. The main growth types of clonal plants are the guerrilla and phalanx types. However, little is known about the effects of these different clonal growth types on plant plasticity in response to heterogeneous resource distribution. We compared the growth performance of clonal wetland plants exhibiting the two growth forms (guerrilla growth form: Scirpus yagara, Typha orientalis, Phragmites australis and Sparganium stoloniferum; phalanx growth form: Acorus calamus, Schoenoplectus tabernaemontani and Butomus umbellatus) grown in soil substrates that were either homogeneous or heterogeneous but had the same total amount of nutrients. RESULTS: We found that the morphological traits (plant height, ramet number, spacer diameter and length) and biomass accumulation of the guerrilla clonal plants (T. orientalis) were significantly enhanced by heterogeneity, but those of the phalanx clonal plants (A. calamus, S. tabernaemontani and B. umbellatus) were not. The results showed that the benefits of environmental heterogeneity to clonal plants may be correlated with the type of clonal structure. CONCLUSIONS: Guerrilla clonal plants, which have a dispersed, flexible linear structure, are better suited to habitats with heterogeneous resources. Phalanx clonal plants, which form compact structures, are better suited to habitats with homogeneous resources. Thus, wetland clonal species with the guerrilla clonal structure benefit more from soil nutrient heterogeneity.

Asymptotic Capacity Results on the Discrete-Time Poisson Channel and the Noiseless Binary Channel with Detector Dead Time.

This paper studies the discrete-time Poisson channel and the noiseless binary channel where, after recording a 1, the channel output is stuck at 0 for a certain period; this period is called the "dead time." The communication capacities of these channels are analyzed, with main focus on the regime where the allowed average input power is close to zero, either because the bandwidth is large, or because the available continuous-time input power is low.

T2 mapping of cartilage and menisci at 3T in healthy subjects with knee malalignment: initial experience.

PURPOSE: To assess the relationship between knee alignment and T2 values of femorotibial cartilage and menisci in healthy subjects at 3 T. MATERIALS AND METHODS: Thirty-six healthy subjects divided into three subgroups of 12 neutral, 12 varus, and 12 valgus alignment of the femorotibial joint were investigated on 3-T MR scanner using a 2D multi-echo turbo spin-echo (TSE) sequence for T2 mapping. Wilcoxon signed-rank test and analysis of covariance (ANCOVA) were performed to determine any statistically significant differences in subregional T2 values of femorotibial cartilage and menisci among the three subgroups of healthy subjects. RESULTS: Lateral femoral anterior cartilage subregion (52 ± 3 ms, mean ± standard deviation; 53 ± 2 ms) had significantly higher T2 values (p < 0.05) than medial femoral anterior cartilage subregion (51 ± 2 ms; 51 ± 2 ms) in varus and valgus groups, respectively. There were statistically significant differences (p < 0.05) in T2 values of tibial central cartilage subregion between lateral and medical compartment among varus, valgus, and neutral subgroups. Lateral body segment of meniscus (41 ± 3 ms) had significantly higher (p < 0.05) T2 values than medial body segment (40 ± 2 ms) in the varus subgroup. CONCLUSIONS: Some degree of correlation between knee alignment and subregional T2 values of femorotibial cartilage and menisci exists in healthy subjects. These findings indicate that T2 mapping may be sensitive in assessing the load distribution pattern of human cartilage and menisci with knee alignment abnormality, which may be used as reference baseline when understanding the occurrence and progression of knee osteoarthritis.

T1ρ MRI of human musculoskeletal system.

Magnetic resonance imaging (MRI) offers the direct visualization of the human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium, etc. Conventional MRI techniques based on T1 - and T2 -weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage, with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article we focus on cartilage biochemical composition, basic principles of T1ρ MRI, implementation of T1ρ pulse sequences, biochemical validation, and summarize the potential applications of the T1ρ MRI technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we also review the potential advantages, challenges, and future prospects of T1ρ MRI for widespread clinical translation.

T1rho MRI at 3T of menisci in patients with acute anterior cruciate ligament (ACL) injury.

PURPOSE: To explore the feasibility of T1rho mapping of menisci at 3T in discriminating between patients with acute anterior cruciate ligament (ACL) injury and healthy controls. MATERIALS AND METHODS: Thirty-three subjects were included in the study and subdivided into two subgroups: 16 healthy controls (4 females, 12 males; mean age = 34.4 ± 10.2 years, age range 24-63 years), 17 patients with ACL injury (3 females, 14 males; mean age = 29.8 ± 10.8 years, age range 18-61 years). T1rho images from all subjects were acquired on a 3T MR scanner using a spin-lock-based 3D GRE sequence and computed for T1rho mapping. Clinical proton density (PD)-weighted fast spin echo (FSE) images in the sagittal (without fat saturation), axial, and coronal (fat-saturated) planes were also acquired for cartilage assessment using Whole-Organ MR Imaging Score (WORMS) grading. Mixed model two-way analysis of variance (ANOVA) was performed to determine whether there were any significant differences among subregional, compartmental, and whole structure T1rho values of meniscus between healthy controls and ACL-injured patients. RESULTS: Lateral posterior (29 ± 8 msec) and medial central (25 ± 7 msec) meniscus subregions in healthy controls had significantly lower T1rho values (P < 0.05) than the corresponding meniscus subregions in ACL-injured patients. Significantly lower meniscus T1rho values (P < 0.05) were also identified in lateral compartment in healthy controls (26 ± 6 msec) than that of ACL-injured patients (33 ± 4 msec). Subjects' total WORMS between healthy controls and ACL-injured patients had significant differences (P < 0.05). CONCLUSIONS: These preliminary results indicate that T1rho mapping is possibly feasible in detecting meniscus degeneration and may be useful in distinguishing ACL-injured patients.

T1rho MRI of menisci in patients with osteoarthritis at 3 Tesla: a preliminary study.

PURPOSE: To compare and assess subregional, compartmental, and whole T1rho values of menisci in patients with doubtful-minimal (Kellgren-Lawrence [KL] grade 1-2) as compared to moderate-severe (KL3-4) osteoarthritis (OA) and healthy controls at 3 Tesla (T). MATERIALS AND METHODS: Forty-six subjects were included in the study and subdivided into three subgroups: 16 healthy controls (4 females, 12 males; mean age = 34.4 ± 10.2 years; age range, 24-63 years), 20 patients with doubtful-minimal (KL1-2) OA (9 females, 11 males; mean age = 61.9 ± 10.8 years; age range, 40-80 years), and 10 patients with moderate-severe (KL3-4) OA (4 females, 6 males; mean age = 71.1 ± 9.6 years; age range, 58-89 years). All subjects were evaluated on a 3T MR scanner using a spin-lock-based three-dimensional GRE sequence for T1rho mapping. Clinical proton density (PD)-weighted fast spin echoes (FSE) images in the sagittal (without fat saturation), axial, and coronal (fat-saturated) planes were acquired for cartilage Whole-Organ MR Imaging Score (WORMS) grading. Analysis of covariance was performed to determine whether there were any statistically significant differences between subregional, compartmental, and whole T1rho values of meniscus among healthy controls, OA patients with KL1-2 and with KL3-4. RESULTS: Lateral anterior (median ± interquartile range: 26 ± 3 ms) and medial posterior (29 ± 6 ms) meniscus subregions in healthy controls had significantly lower T1rho values (P < 0.05) than the corresponding meniscus subregions in both KL1-2 (29 ± 7 ms and 35 ± 8 ms, respectively) and KL3-4 (30 ± 12 ms and 40 ± 13 ms, respectively) OA subjects. Significantly lower meniscus T1rho values (P < 0.05) were also identified in the medial compartment in healthy controls (28 ± 5 ms) relative to both KL1-2 OA subjects and KL3-4 OA subjects (32 ± 7 ms and 37 ± 7 ms, respectively). The entire meniscus T1rho values in healthy controls (28 ± 4 ms) were significantly lower than those of both KL1-2 and KL3-4 OA subjects (33 ± 6 ms and 34 ± 6 ms, respectively). CONCLUSION: Significant elevations of T1rho values in specific regions of menisci in both KL1-2 and KL3-4 OA patients indicate that T1rho mapping may be sensitive to meniscus degeneration. The preliminary results suggest that damage in the medial posterior subregion and medial compartment of menisci may possibly be associated with osteoarthritis.

Study on the synthesis and structure-effect relationship of multi-aryl imidazoles with their fluorescence properties.

In this paper, 23 multi-aryl imidazole derivatives were synthesized and identified by nuclear magnetic resonance, ultraviolet-visible and elemental analysis. At the same time, their ultraviolet-visible maximum absorption (λ(ab)(max)), fluorescence emission maximum (λ(em)(max)) and quantum yields (Ф(f)) were measured. The relationships between the optical behaviors and structures for these compounds were assessed. The results show that the λ(max)(ab) and λ(max)(em) are red-shifted and the fluorescence Ф(f) are increased by the introduction of electron-withdrawing substituents and the increase in the planarity of multi-aryl imidazole molecules. The results also showed that the fluorescence quantum yields of the compounds containing two imidazole nuclei are double the corresponding mono-imidazole nucleus compounds.

Machine learning-based prediction of methane production from lignocellulosic wastes.

The biochemical methane potential test is a standard method to determine the biodegradability of lignocellulosic wastes (LWs) during anaerobic digestion (AD) with disadvantages of long experiment duration and high operating expense. This paper developed a machine learning model to predict the cumulative methane yield (CMY) using the data of 157 LWs regarding physicochemical characteristics, digestion condition and methane yield, with the coefficient of determination equal to 0.869. Model interpretability analyses underscored lignin content, organic loading, and nitrogen content as pivotal attributes for CMY prediction. For the feedstocks with a cellulose content exceeding about 50%, the CMY in the early AD stage would be relatively lower than those with low cellulose content, but prolonging digestion time could promote methane production. Besides, lignin content in feedstock surpassing 15% would significantly inhibit methane production. This work contributes to valuable guidance for feedstock selection and operation optimization for AD plants.

Performance and mechanism of various microaerobic pretreatments on anaerobic digestion of tobacco straw.

Tobacco straw is an abundant biomass in China's agricultural ecosystems, and has high potential for methane production. However, the anaerobic digestion (AD) efficiency is limited by the recalcitrant lignocellulose structure of the tobacco straw. In this study, three microaerobic pretreatments were performed for the AD of tobacco straw to increase methane production. Among them, microbial pretreatment with biogas slurry at an oxygen concentration of 4 mL/g VS resulted in the highest methane production of 349.1 mL/g VS, increasing by 19.8 % than that of untreated. During this pretreatment, the relative abundances of Enterococcus and Clostridium sensu stricto 12, which are closely related to acetic acid production and cellulose degradation, were high, and these bacteria might have an important contribution to substrate hydrolysis and the methanogenesis efficiency of the AD process. This study advances the understanding of microaerobic pretreatment processes and provides technological guidance for the efficient utilization of tobacco straw.

Enhancing acidification efficiency of vegetable wastes through heat shock pretreatment and initial pH regulation.

Anaerobic digestion (AD) technology is a practical approach to alleviate severe environmental issues caused by vegetable wastes (VWs). However, its primary product is methane-rich biogas converted from the precursors (mainly volatile fatty acids, VFAs) after long fermentation periods, making traditional AD projects of low economic profits. Intervening in the methanogenesis stage artificially to produce high value-added VFAs can shorten the reaction time of the AD process and significantly improve profits, posing a promising alternative for treating VWs. Given this, this study applied heat shock (HS) pretreatment to inoculum to prevent methane production during AD and systemically investigated the effects of HS pretreatment and initial pH regulation on VFA production from VWs. The results showed that appropriate HS pretreatment effectively inhibited methane generation but promoted VFA accumulation, and VFA production was further enhanced by adjusting the initial pH to 8.0 and 9.0. The highest total VFA concentration of 14,883 mg/L with a VFA yield of 496.1 mg/gVS, 26.98% higher than that of the untreated group, was achieved at an initial pH 8.0 with HS pretreatment of 80 °C for 1 h. Moreover, pH regulation influenced the metabolic pathway of VFA production from VWs during AD, as butyrate was the dominant product at an initial pH of 6.0, while the increased initial pH improved the acetate proportion.

[Isolation and identification of human endometrial stromal stem cells].

OBJECTIVE: To isolate, culture and identify of human endometrial stromal stem cells. METHODS: Endometrial tissue was obtained from 10 women undergoing hysterectomy. Purified stromal stem cell suspensions were then obtained by selecting cells with magnetic bead sorting and colony-forming. The surface markers of stromal cell were identified by flow cytometry. Proliferation of stromal stem cell was observed by MTT methods. The osteogenic potential was evaluated by alizarin red staining, the adipogenic potential by oil red O staining. Then the adipogenic and osteogenic specific markers of differentiated cells assayed by RT-PCR method. Expression of cell surface antigen OCT-4 was detected with immunocytochemical staining. RESULTS: Endometrial stem cells were successfully isolated from human endometrial tissue. They were stably proliferated and subcultured in vitro. Most of the passage cells expressed mesenchymal stem cell markers CD90, CD105 but not hemopoietic markers CD34, CD45. The analysis of cell cycle indicated that the percentage of G2-M phase and S phase cells increased. The growth curves of the third passage presented in "S" shape. After cultured in differentiation medium, the cells differentiated toward adipoblasts and osteoblasts as verified by positive staining with Oil Red O and alizarin red staining. Under induction,cells expressed osteogenic and adipogenic marker genes. The immunocytochemical staining of OCT-4 was positive. CONCLUSION: Human endometrium contains endometrial stromal stem cells, which present characteristics of mesenchymal stem cells and may be used as seed cells for tissue engineering.

Changes in the IL-18, IL-22, and T lymphocyte subset levels in patients with hepatitis B-related liver cirrhosis and their predictive values for hepatorenal syndrome.

OBJECTIVE: To investigate the changes in the interleukin (IL)-18, IL-22, and T lymphocyte subset levels in patients with hepatitis B-related liver cirrhosis and to determine their predictive values for hepatorenal syndrome (HRS). METHODS: Clinical data of 70 healthy individuals (group A) and 84 patients with hepatitis B-related liver cirrhosis (group B) admitted to Hospital 989 of the PLA Joint Logistics Support Force were retrospectively collected. The serum levels of IL-18 and IL-22, concentrations of cluster of differentiation (CD)3+, CD4+, and CD8+ cells, as well as the CD4+/CD8+ ratio in the peripheral blood T lymphocyte subsets were measured. Further, their predictive values for HRS were determined. Logistic regression analysis was employed to identify independent risk factors for HRS. RESULTS: In group B, the posttreatment IL-18 and IL-22 levels and CD8+ cell concentration significantly decreased after treatment, whereas the CD3+ and CD4+ cell concentrations and CD4+/CD8+ ratio increased. Notably, the serum IL-18 and IL-22 levels were higher in patients with HRS than in those without. Also, the CD3+ and CD4+ cell concentrations and CD4+/CD8+ ratio in the peripheral blood were lower in patients with HRS than in those without. The sensitivities of the serum IL-18 and IL-22 levels for predicting HRS were 90.32% and 80.65%, and the specificities were 71.70% and 77.36%, respectively. The sensitivities of CD3+, CD4+, and CD8+ cell concentrations for predicting HRS were 77.42%, 90.32%, and 83.87%, and the specificity was 67.92%, 64.15%, and 52.83%, respectively. Moreover, the sensitivity and specificity of CD4+/CD8+ ratio for predicting HRS were 80.65% and 86.79%, respectively. CONCLUSIONS: IL-18, IL-22, and T lymphocyte subset levels may have significant implications in the progression of hepatitis B-related liver cirrhosis, and detecting these markers could aid in treatment, evaluation, and prediction of HRS in patients. Furthermore, IL-18 and IL-22 levels and the CD4+/CD8+ ratio were identified as independent risk factors for HRS.

In situ remediation mechanism of internal nitrogen and phosphorus regeneration and release in shallow eutrophic lakes by combining multiple remediation techniques.

Large anthropogenic inputs of N and P alter the nutrient cycle and exacerbate global eutrophication problems in aquatic ecosystems. This study in Lake Datong, China, investigates the remediation mechanism of multiple remediation technique combinations (dredging, adsorbent amendment, and planting aquatic vegetation) on sediment N and P loads based on two high-resolution sampling techniques (HR-Peeper and DGT) and P sequential extraction procedures. The results showed that high temperature and low dissolved oxygen considerably enhanced pore water dissolved reactive P (DRP) and NH4+ concentrations attributable to abundant Fe-P and organic matter content in the sediment. Fe reduction is critical for regulating pore water DRP release and promoting N removal. Overall, for Lake Datong, combining multiple remediation techniques is more effective in controlling sediment P loads (pore water DRP, P fluxes, forms of P, and labile P), from a long-term perspective, than a single remediation. Lanthanum-modified bentonite (LMB) inactivation treatment can transfer mobile P in the surface sediment into more refractory forms over time, thereby reducing the risk of sediment labile P release. However, it is difficult to effectively remediate internal P loads owing to inappropriate dredging depths and low biomass of aquatic vegetation. Future lake restoration practices should optimize the selection of different remediation technique combinations based on internal N and P pollution characteristics, while reducing external wastewater input. These results are important for understanding the remediation mechanisms of internal N and P and provide suggestions for sediment management of shallow eutrophic lakes.

Imaging parameters and clinical significance of posterior ligament complex injury in thoracolumbar fracture.

This study aims to investigate whether the combination of radiographs and computed tomography (CT) images can be used as an alternative means of magnetic resonance imaging examination or a preliminary screening method before examination, so as to improve the accuracy of determining the degree of posterior ligament complex injury in thoracolumbar fracture patients. From May 2011 to May 2019, the patients with thoracolumbar fracture were collected. A total of 150 patients were enrolled. The reference standard was 1.5T magnetic resonance imaging examination and lipid suppression sequence was applied. All radiographs and CT imaging results were measured in the Picture Archiving and Communication System workstation. The upper endplate angle and lower endplate angle, the percentage of vertebral height drop, the difference of inter-spinous process distance on CT images and the translation distance were statistically significant between the 2 groups (P < .05). Receiver operating characteristic curve showed that the diagnostic performance was excellent (all area under the curve > 0.7). To sum, the results showed that endplate angle + inter-spinous process distance on CT images combination had relatively high-quality diagnostic value for posterior ligamentous complex injury in thoracolumbar fracture patients.

Assessment of subchondral bone marrow lipids in healthy controls and mild osteoarthritis patients at 3T.

The compartment-specific lipid changes in femoral-tibial bone of healthy controls and mild osteoarthritis (OA) patients were quantified at 3.0 T. Healthy volunteers [Kellgren-Lawrence (KL) grade = 0; n = 15, 4 females, 11 males, mean age 39 ± 16 years, age range = 24-78 years] and mild OA patients (KL = 1, 2; n = 26, 12 females, 14 males, mean age 61 ± 14 years, age range = 27-80 years) were scanned on a 3 T scanner. Clinical proton density (PD)-weighted fast spin echo (FSE) images in the sagittal (without fat-saturation), axial and coronal (fat-saturation) planes were acquired for cartilage Whole-Organ MR Imaging Score (WORMS) grading. A voxel of 10 × 10 × 10 mm(3) was positioned in the medial and lateral compartments of the tibia [medial tibial (MT) and lateral tibial (LT)] and femur [medial femoral (MF) and lateral femoral (LF)] for MRS measurements using the single voxel-stimulated echo acquisition mode (STEAM) pulse sequence. All MRS data were processed with Java-based Magnetic Resonance User Interface (JMRUI). Wilcoxon's rank sum test and mixed model two-way analysis of variance (ANOVA) were performed to determine significant differences between different compartments as well as examine the effect of OA grade and compartment, and their interactions. Generally, the MF compartment index of unsaturation was increased in healthy subjects compared with OA subjects (whether graded by KL or WORMS score). Differences between MF at KL0 and all other compartments at KL1 except LF approached statistical significance (p < 0.05). Differences in saturated lipids signals could be observed predominantly in the 2.03 p.p.m. frequency shift. Healthy controls in the MF compartment had the lowest saturated lipid signals, and mild OA patients with KL2 and WORMS5-6 in the MF compartment had the highest saturated lipid signals compared with other compartments at 2.03 p.p.m. (p < 0.05).

One-shot classical-quantum capacity and hypothesis testing.

The one-shot classical capacity of a quantum channel quantifies the amount of classical information that can be transmitted through a single use of the channel such that the error probability is below a certain threshold. In this work, we show that this capacity is well approximated by a relative-entropy-type measure defined via hypothesis testing. Combined with a quantum version of Stein's lemma, our results give a conceptually simple proof of the well-known Holevo-Schumacher-Westmoreland theorem for the capacity of memoryless channels. More generally, we obtain tight capacity formulas for arbitrary (not necessarily memoryless) channels.