From lake to fisheries: Interactive effect of climate and landuse changes hit on lake fish catch?

Global warming and unpredictable nature possess a negative impact on fisheries and the daily activities of other habitats. GIS and remote sensing approach is an effective tool to determine the morphological characteristics of the lake. The present study addresses the interactive effect of climate and landuse changes hit on fish catch in lake fisheries. We used a combination of the landscape disturbance index, vulnerability index, and loss index to construct a complete ecological risk assessment framework based on the landscape structure of regional ecosystems. The results indicate an increase from around 45%-76% in the percentage of land susceptible to moderate to ecological severe risk in the landscape from 2004 to 2023. Since 1950, temperature changes have increased by 0.4%, precipitation has decreased by 6%, and water levels have decreased by 4.2%, based on the results. The results indicate that landuse, water temperature, precipitation, and water depth significantly impact the aquaculture system. The findings strongly suggest integrating possible consequences of environmental change on fish yield for governance modeling techniques to minimize their effects.

Reconstruction of the medial patellofemoral ligament through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation.

PURPOSE: The present study aimed to assess the clinical efficacy and imaging results of reconstruction of the medial patellofemoral ligament through a double bundle of single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation. METHODS: Twenty-three patients with recurrent patellar dislocation, including ten males and 13 females, with 23 knee joints were enrolled according to the relevant criteria. Reconstruction of the medial patellofemoral ligament was performed through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity. Knee function was evaluated using visual analog scale (VAS) score, International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner score, and Kujala score at pre- and postoperative stages. Patellar stability was assessed by CT scans measuring tibial tuberosity-trochlear groove (TT-TG) distance, lateral patella displacement (LPD), congruence angle (CA), and patellar tilt angle (PTA). RESULTS: All 23 patients were effectively followed up for 13-28 months (mean: 21.91 ± 4.14 months). At the last follow-up, the postoperative VAS score, IKDC score, Lysholm score, Tegner score, and Kujala score of 23 patients were 1.13 ± 0.82, 87.35 ± 3.17, 90.22 ± 1.28, 4.35 ± 0.65, and 89.26 ± 1.96, respectively, as compared to the preoperative values of 5.91 ± 1.13, 30.96 ± 5.09, 30.30 ± 2.98, 1.26 ± 0.62, and 27.87 ± 3.46, respectively, and these differences were statistically significant (P < 0.001). At the last follow-up, the postoperative TT-TG, LPD, CA, and PTA values of the 23 patients were 8.80 ± 1.85 mm, 6.01 ± 1.77 mm, 11.32 ± 6.18°, and 9.35 ± 2.88°, respectively, compared to the preoperative values of 18.77 ± 1.74 mm, 14.90 ± 4.07 mm, 37.82 ± 5.71°, and 23.58 ± 3.24°, respectively, and the differences were statistically significant (P < 0.001). No relevant complications were observed in the 23 patients. CONCLUSIONS: Reconstruction of the medial patellofemoral ligament through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation showed satisfactory medium-term efficacy, and further investigations are required to confirm the long-term efficacy of this approach.

Cold stress after swimming fatigue decreases immunity-related gene expression in the spleen of the Chinese sucker.

For migratory fish, passing through the cold, fast flowing water of a dam causes stress, leading to disease and even death. To determine the immune response to cold stress in a dam-lake after swimming fatigue in Chinese sucker (Myxocyprinus asiaticus), the spleen mRNA expression profiles in response to cold stress (CS) after fatigue stress (FS) were compared with that of the control (SS). We identified 40,952 differentially expressed genes (DEGs) in the spleen for at least one comparison among 211,397 unigenes. We identified 11,869 DEGs (4,968 upregulated and 6,901 downregulated), 17,803 DEGs (10,610 upregulated and 7,193 downregulated), and 30,579 DEGs (20,652 upregulated and 9,927 downregulated) in the SS vs. FS, SS vs. CS, and FS vs. CS comparisons, respectively. Enrichment analysis indicated the involvement of the immune system and infectious diseases, including the toll-like receptor pathway, the complement and coagulation cascade, and the natural killer cell-mediated cytotoxicity pathway. There were 2,991 DEGs (271 upregulated and 2,720 downregulated), and 2,878 DEGs (873 upregulated and 2,005 downregulated) associated with these pathways in the SS vs. FS and SS vs. CS comparisons, respectively. In the cold stress after fatigue group, the expression levels of heat shock protein (HSP) 70 and HSP90 genes were significantly upregulated; however, more immune response genes showed significantly downregulated expression in SS vs. CS compared with that in SS vs. FS, including those encoding tumor necrosis factor, C-C motif chemokines (3, 8, and 13), complement components (C3, C4, C6, and C7), immunoglobulin, and cathepsins. Overall, cold stress combined with swimming fatigue from passing the dam resulted in the downregulation of many immune genes, suggesting that the Chinese sucker might have experienced serious immune suppression.

Swimming behaviour of silver carp (Hypophthalmichthys molitrix) in response to turbulent flow induced by a D-cylinder.

Turbulence is a complex hydraulic phenomenon which commonly occurs in natural streams and fishways. Riverine fish are subjected to heterogeneous flow velocities and turbulence, which may affect their movements and ability to pass the fishways. However, studies focusing on fish response to turbulent flows are lacking for many species. Here we investigate the effects of the turbulence created by a vertical half-cylinder of various diameters (1.9, 2.5, 3.2 and 5.0 cm) on the swimming ability and behaviour of silver carp, Hypophthalmichthys molitrix. The large D-cylinders (3.0 and 5.0 cm) create specific vorticity and reduced velocities areas in their vicinity, which favours flow refuging behaviours (FRBs) and thus increased relative critical swimming speeds (Urcrit , BL/s) of silver carp, by comparison to free-flow conditions and cylinders of smaller diameter (1.9 and 2.5 cm). The flow speed at which silver carp maximized FRBs such as Karman gaiting downstream of the cylinder, holding position in the bow wake or entraining on the side ranged from 40 to 70 cm s-1 , depending on fish body size. When holding station near a cylinder under optimal flow speeds, the distance between the fish and the cylinder is related to the size of the fish, but also to the size of the cylinder and the produced vortices. The optimal holding region in the drag wake of the cylinder ranged from 28 to 40 cm downstream of the centre of the cylinder, depending on the size of the fish. Smaller fish, however, tend to use the reduced velocities areas located in the bow wake of the large cylinders. We hypothesize that fish will display FRBs, including maintaining a Karman gait in turbulent flow, when the ratio of the cylinder diameter to their body length is between 1:3 and 1:4. They also match their tail beat frequency to the vortex shedding frequency of the cylinder. Our results provide a better understanding of how silver carp respond to turbulent flows around physical structures, with implications for the design of nature-like fishways or exclusion devices in both its native and invasive ranges.

Can feeding sound attract flower fish (Ptychobarbus kaznakovi)?

The use of acoustic attractants may have the potential to guide native migratory species towards safe passage. Flower fish Ptychobarbus kaznakovi, a short-distance migratory fish whose population is in decline in the past decades, was exposed to three acoustic stimuli (feeding sound, ambient riverine noise and the pure tone 1000 Hz) to examine the phonotaxic responses using playbacks approaches in a fibreglass tank. The results showed that the flower fish showed significantly greater positive phonotaxis and swam towards the sound sources significantly faster in response to the feeding sounds than to ambient riverine noise and the pure tone during the 5-min exposure. Distribution experiments were conducted to study the preference of flower fish to the three sounds stimuli. The results showed that the experimental fish in feeding sound trials spent significant more time in areas closer to the sound sources than that in the pure tone and the ambient riverine noise trials, respectively. This study indicates that the feeding sounds may serve as potential acoustic attractants to guide flower fish to safe passage routes.

Microplastics abundance, distribution and composition in surface waters, sediments and fish species from Amir-Kalayeh Wetland, Northern Iran.

Microplastics (MPs) pollution is considered as a globally pervasive threat to aquatic ecosystems and many studies reported this pollution in different aquatic ecosystems. However, studies on MPs pollution in wetlands are still scarce. Therefore, the aim of present study was to investigate the presence of MPs in the surface water, sediment and different fish species of Amir-Kalayeh wetland, Northern Ian. Surface water and sediment samples were collected from six stations during June to July 2022. Moreover, the gills and gastrointestinal tract (GIT) of 54 fish specimens belonging to four species including Cyprinus carpio, Tinca tinca, Esox lucius and Silurus glanis were analysed. MPs were detected in all samples with an average of 2.15 ± 1.98 items/m3 for surface water, 51.66 ± 32.20 items/kg dry weight for sediments, 0.17 ± 0.17 items/individual for fish GIT and 0.12 ± 0.12 items/individual for fish gills. There was no significant relationship between MPs abundance in surface waters and sediments as well as between MPs abundance in environmental matrices and fish (P > 0.0.5). In terms of feeding habit, no significant differences were observed between the number of MPs found in omnivorous and carnivorous fish species (P > 0.05). Moreover, no significant relationship was detected between the MPs abundance in fish tissues and body size (P > 0.05). MPs were mainly fibers, mostly transparent, and in a range size of 70-5000 µm. The dominant MPs type was nylon in all samples. This study will help increase our knowledge about MPs pollution in inland freshwater systems and suggests that management policies take essential steps to reduce this insidious problem in freshwater ecosystems.

Potential use of gammarus (Pontogammarus maeoticus) and shrimp (Palaemon elegans) as biomonitors of microplastics pollution in coastal environments.

Microplastics (MPs) pose a significant threat to marine ecosystems, necessitating robust biomonitoring to assess aquatic risks and inform effective policymaking. In this study we investigated MPs pollution in gammarus (Pontogammarus maeoticus), shrimp (Palaemon elegans), sediment and water samples of southern coast of the Caspian Sea to assess the potential use of these two crustaceans as biomonitors of MPs pollution, bioconcentration of MPs in organisms' tissue and the pollution risks of MPs in environmental matrices. Samples were collected from 6 stations during June to August 2023. MPs were found in all compartments with an average of 100 ± 45.34 items/kg dry weight, 0.45 ± 0.06 items/L, 0.38 ± 0.21 items/individual or 0.58 ± 0.34 items/g wet weight (ww) and 0.26 ± 0.15 items/individual or 8.69 ± 7.88 items/g ww, for sediments, seawaters, P. elegans and P. maeoticus, respectively. MPs were prevailed by class 300-1000 µm in size, polyamide in polymer, fiber in shape and black in color. P. maeoticus and P. elegans did not meet the selection criteria as MPs biomonitors. However, bioconcentration factor (BCF) illustrated that both crustaceans can absorb and accumulate MPs from their surrounding water (BCF >1). Based on contamination factors (CF) values, sampling stations were polluted with MPs (1 ≤ CF < 6). The overall pollution load index (PLI) for sediment and seawater stations were 2.47 and 1.88, respectively, indicating minor contamination with MPs in the risk level I. Current research provides useful information on MPs pollution in crustaceans species and the risk level of MPs in environmental matrices that can be suitable for bioaccumulation hazard assessment and future monitoring programs.

Quantitative Assessment and Regulation of Passage and Entrance Attraction Efficiency of Vertical-Slot Fishway on Heishuihe River in Southwest China.

Fish passage facilities are essential for restoring river connectivity and protecting ecosystems, effectively balancing economic and ecological benefits. Systematic and comprehensive monitoring, assessment, and optimized management are therefore crucial. This study quantitatively evaluated the entire upstream migration process of fish from the downstream river to the entrance and exit of the fishway and investigated the upstream movement patterns of fish under various environmental factors. A total of 19 fish species were monitored in the Heishuihe River downstream of the dam, with 15 species reaching the fishway entrance and 12 species successfully passing through it. The entrance attraction and passage rates of the vertical-slot fishway at the Songxin hydropower station were 15.7% and 40.42%, respectively. The best upstream performance was observed in May, with fish demonstrating better upstream timing and speed during nighttime compared to daytime. Specifically, the highest entrance attraction efficiency was recorded at a flow rate of 6-7 m3/s and a temperature of 19-20 °C, while the optimal passage efficiency was observed at a flow rate of 0-0.5 m3/s and a temperature of 17-20 °C. Additionally, a multifactorial Cox proportional hazards regression model was constructed to identify key factors influencing the probability of fishway entrance attraction and successful passage. The model elucidated the impact patterns of these key factors on fish upstream migration, ultimately generating an alignment diagram for prediction and control. This study provides a theoretical foundation and data support for developing optimized operational schedules for fishways. The findings offer a more comprehensive and systematic approach for monitoring and evaluating fish passage facilities, serving as a scientific basis for ecological restoration and fish conservation in this region and similar areas.

Continuous flow stimulation had no significant effect on the growth rate but was conducive to the swimming performance, spontaneous behavior, and nonspecific immune parameter of juvenile Percocypris pingi.

Flow stimulation before release into the wild may contribute to improved survivability of farmed fish. However, the effects of flow stimulation on the survival rate of fish depend on the fish species and exercise regime, such as exercise type, duration, and intensity. In this study, juvenile Percocypris pingi swam for 18 h per day for 8 weeks under different water speeds, 3 cm s-1 (control) and 1, 2, and 4 body lengths (bl) s-1 , at 20°C. Then, parameters related to the growth rate, swimming capacity, spontaneous activity, and immune function were measured. We found that (1) continuous flow stimulation had no significant influence on the growth but was conducive to the increase in the relative carcass mass; (2) continuous flow stimulation at 2 or 4 bl s-1 enhanced the aerobic swimming capacity (Ucrit ), which may be due to an increase in anaerobic exercise capacity (endurance time) rather than to changes in maximum metabolic rate and aerobic scope; (3) continuous flow stimulation at 4 bl s-1 led to a significant increase in spontaneous activity, which was mainly due to the higher percent time spent moving as compared with the controls; and (4) continuous flow stimulation at 2 bl s-1 may contribute to improving the nonspecific immune parameter (lysozyme activity) in juvenile P. pingi. Our findings suggest that continuous flow stimulation at 2 or 4 bl s-1 for 18 h per day for 56 days at 20°C before release in wild may be a suitable training regime for improving the survival rate of cultured juvenile P. pingi.

Transcriptome analysis of Chinese sucker (Myxocyprinus asiaticus) head kidney and discovery of key immune-related genes to cold stress after swimming fatigue.

For Chinese sucker (Myxocyprinus asiaticus), passing through a dam with fast flow and cold water are always unavoidable, and this process can cause stress, disease or even death. In this study, comparative transcriptome analysis was conducted to investigate the potential immune mechanism in head kidney of M. asiaticus with swimming fatigue stress and cold stress after fatigue. In general, a total of 181,781 unigenes were generated, and 38,545 differentially expressed genes (DEGs) were identified. In these DEGs, 22,593, 7286 and 8666 DEGs were identified among groups of fatigue vs. cold, control vs. cold, and control vs. fatigue, respectively. Enrichment analysis revealed these DEGs were involved in coagulation cascades and complement, natural killer cell mediated cytotoxicity, antigen processing and presentation, Toll-like receptor signaling pathways, and chemokine signaling pathway. Notably, immune genes including heat shock protein 4a (HSP4a), HSP70 and HSP90α genes were significantly up-regulated in fishes with cold stress after fatigue. Differently, more immune genes in control vs. cold compared with that in control vs. fatigue were significantly down-regulated expression, such as claudin-15-like, Toll-like receptor 13, antimicrobial peptide (hepcidin), immunoglobulin, CXCR4 chemokine receptor, T-cell receptor, complement factor B/C2-A3, and interleukin 8. In this study, the number of DEGs in the head kidney was less than that our previous study in the spleen, which we speculated was more sensitive to changes in water temperature than the head kidney. In summary, lots of immune-related genes in the head kidney were down-regulated under cold stress after fatigue, suggesting that M. asiaticus might have experienced severe immunosuppression in the process of passing through the dam.

Numerical Simulation and Deep Neural Network Revealed Drag Reduction of Microstructured Three-Dimensional Square Cylinders at High Reynolds Numbers.

Square cylinders are widely used in various fields. For example, they are common structures in fishways. The flow around square cylinders has been a common problem in various fields. However, reducing the flow drag of the square cylinder is a problem that remains unexplored. Many previous studies have reported the drag reduction of 2D square cylinders, which failed to reflect the drag of real structures. Also, some studies focus on the drag force of the inner wall of the square cylinder modified by the microstructure. Achieving drag reduction by microstructuring the surface of the 3D square cylinder is a challenging problem. This study applied a 3D numerical simulation and deep neural network to study the drag reduction performance of the square cylinder under different patch sizes. We studied the drag reduction performance of protrusion and pit-patched square cylinders and tried to find the rule between drag reduction performance and patch configuration. The results show that the square cylinder has better drag reduction performance in some cases. However, its drag reduction performance is greatly affected by the protrusion structure. Also, too large protrusions will increase the drag force of the structure. When the surface protrusion accounts for 10% of the total area of the square cylinder, the drag reduction performance is the best (22.1%). The pit patch structure demonstrated an insignificant drag reduction performance and even increased the drag in most cases. The DNN prediction model demonstrated the robustness of the numerical simulation data.

Polystyrene microplastics induced male reproductive toxicity and transgenerational effects in freshwater prawn.

Microplastics have become pervasive environmental pollutants, especially in freshwater rivers and lakes. However, how freshwater prawns' reproductive system is affected by polystyrene microplastics (PS-MPs) remains incompletely understood. Thus, the present study aimed to determine the effect of PS-MPs on the male reproductive system and offspring larval immunity in oriental river prawn. Acute exposure to PS-MPs decreased the survival rate and heart rate of prawn larvae. After chronic exposure to PS-MPs (2 and 20 mg/L) for four weeks, the oxidative stress generation in testis tissue indicated a negative impact on male prawn testicular function. PS-MPs disrupted testicular germ cell quality and caused sex hormone imbalance, leading to reduced hatching success and survival of F1 larvae, despite not being exposed to PS-MPs. Steroidogenic gene expression was altered and apoptosis-related genes had higher expression in the gonads after parental exposure to PS-MPs. Decreased immunity-related enzyme activities were observed in F1 larvae with/without continued PS-MPs exposure, compared with those in untreated prawns. A concentration-dependent increase in bioaccumulation of PS-MPs in different tissues of larval offspring was observed. Thus, PS-MPs had multiple effects on male reproductive dysfunction and transgenerational toxicity in prawns. Our findings provide a novel insight into the reproductive toxicity mechanism of microplastics in freshwater crustaceans.

Effects of Aerobic Exercise Training on the Growth, Swimming Performance, Antipredation Ability and Immune Parameters of Juvenile Rock Carp (Procypris rabaudi).

Many studies have found that aerobic exercise training at a moderate water velocity can improve the growth, swimming performance and survival rate of fish. To investigate the effects of aerobic exercise training on the growth, swimming performance, antipredation ability and immune parameters of rock carp, juveniles were placed in training channels with different water velocities (i.e., 3 cm s-1, 1 (body length s-1) bl s-1, 2 bl s-1 and 4 bl s-1) for 6 weeks. Then, the specific growth rate, critical swimming speed (Ucrit) and its metabolism, constant acceleration speed (Ucat), survival rate under predation, spleen index, lysozyme (LZM) activity and immunoglobulin (IgM) level were measured. Training showed no significant effect on the length-specific growth rate, weight-specific growth rate, Ucrit, maximum metabolic rate (MMR), metabolic scope (MS), Ucat or spleen index. The resting metabolic rates (RMRs) of the 2 bl s-1 and 4 bl s-1 training groups were significantly higher than those of the control group and 1 bl s-1 training group. The survival rate of the 1 bl s-1 training group in the presence of predators was significantly higher than that of the control group but significantly lower than those of the 2 bl s-1 and 4 bl s-1 training groups. The LZM activity of the 4 bl s-1 training group was significantly higher than that of the control group. The IgM level of the 2 bl s-1 training group was significantly higher than that of the control group. These data indicate that aerobic exercise training does not improve the growth and swimming performance of juvenile rock carp but can improve their antipredation ability and immunologic function.

Analysis of Movements and Behavior of Bighead Carps (Hypophthalmichthys nobilis) Considering Fish Passage Energetics in an Experimental Vertical Slot Fishway.

An understanding of fish movement behavior in response to flow field variables is important for exploring the hydrodynamic strategies of fish in fish passages. In this paper, bighead carps were taken as an example. The fish movement behavior response to water flow field information by means of estimating the energetic expenditure using an IBM approach in an experimental fishway was investigated. Fish swimming velocity, drag force, and energy expenditure were analyzed in varied flow conditions related to hydraulic variables, including velocity (V), turbulent kinetic energy (TKE), and strain rate (SR). The result indicated that the fish will require more energy in high TKE zones. This study provides a reference for optimizing the design of fish passages and fisheries management. This method can be applied to assess the efficiency of fish bypass structures and conduct fish survival studies.

A Detailed Analysis of the Effect of Different Environmental Factors on Fish Phototactic Behavior: Directional Fish Guiding and Expelling Technique.

Optimization of light-based fish passage facilities has attracted extensive attention, but studies under the influence of various environmental factors are scarce. We established a novel experimental method to measure the phototactic behavior of Schizothorax waltoni. The results showed that S. waltoni preferred the four light colors in the order green, blue, red, and yellow. The increased flow velocity intensified the positive and negative phototaxis of fish under different light environments, while an increase in the water temperature aroused the escape behavior. The escape behavior of fish in red and yellow light and the phototaxis behavior in green and blue light intensified as the light intensity exceeded the phototaxis threshold and continued to increase. Thus, red or yellow light greater than the phototaxis threshold can be used to move fish away from high-turbulent flows or polluted waters, while green or blue light can be used to guide them to fish passage entrance or ideal habitats. This study provides scientific evidence and application value for restoring fish habitats, fish passages, and fisheries.

The Kinematics and Dynamics of Schizopygopsis malacanthus Swimming during Ucrit Testing.

The swimming kinematics (how fish move) and dynamics (how forces effect movement) of Schizopygopsis malacanthus were investigated during the determination of Ucrit by stepped velocity testing. A video tracking program was used to record and analyze the motion of five test fish in a Brett-type flume during each velocity step. The findings fell into three groups: (1) Even when flow was uniform, fish did not swim steadily, with speeds fluctuating by 2.2% to 8.4% during steady swimming. The proportion of unsteady swimming time increased with water velocity, and defining steady and unsteady swimming statistically, in terms of the definition of standard deviation of instantaneous displacements, may have higher accuracy. (2) In steady swimming, the forward velocity and acceleration of fish were correlated with body length (p < 0.05), but in unsteady swimming the correlations were not significant. The maximum swimming speed (1.504 m/s) and acceleration (16.54 m/s2) occurred during unsteady swimming, but these measurements may not be definitive because of tank space constraints on fish movement and the passive behavior of the test fish with respect to acceleration. (3) Burst-coast swimming in still water, investigated by previous scholars as an energy conserving behavior, is not the same as the gait transition from steady to unsteady swimming in flowing water. In this study, the axial force of fish swimming in the unsteady mode was significantly higher (×1.2~1.6) than in the steady mode, as was the energy consumed (×1.27~3.33). Thus, gait transition increases, rather than decreases, energy consumption. Our characterization of the kinematics and dynamics of fish swimming provides important new information to consider when indices of swimming ability from controlled tank testing are applied to fish passage design.

In vivo visualization assay to evaluate the effects of maternal exposure to mercury on offspring bioaccumulation in the oriental river prawn (Macrobrachium nipponense).

Mercury (Hg) is a persistent pollutant that accumulates in aquatic animals. However, studies related to understand how gonad tissue of this species responds to mercury exposure and elucidation of mercury bioaccumulation in crustacean offspring by cross-generational, are still sparse. The present study aimed to assess the bioaccumulation of Hg2+in vivo in prawn offspring by a specific aggregation-induced emission fluorogen (AIEgen). The 96 h median lethal concentration (LC50) values of mercury to the juveniles were 0.072 mg/L. Hg2+ reduced growth performance, damaged oocyte quality, and inhibited ovary maturation, thus inhibiting gonadal maturation in intact prawns. F1 offspring were exposed to Hg2+ by direct transfer from their F0 parents, as shown by the distribution of mercury in gonads and fertilized eggs. In the medium containing oriental river prawn larvae, the Hg2+ concentration decreased rapidly, indicating fast initial larval uptake of Hg2+. Due to metal ion triggered AIE activity, analysis of fluorescence images showed that prawn offspring accumulated Hg2+ via maternal transfer, and there was a relationship among the photoluminescence intensity, the AIEgen concentration, and mercury levels. The quantitative detection of Hg2+ absorption from prawn larvae by the AIEgen represents a novel analytical technique to understand the dynamics of Hg2+ between maternal and offspring.

Evaluation of Accuracy of Preoperative Planning of the Femurofibular Angle in Open-Wedge High Tibial Osteotomy for Mild Medial Knee Osteoarthritis.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of preoperative planning of the femurofibular angle (FFA) in medial open-wedge high tibial osteotomy (OWHTO) for mild medial knee osteoarthritis. METHODS: Thirty-two patients (32 knees) with mild medial knee OA were retrospectively reviewed. The patients underwent preoperative planning of the FFA for OWHTO. For preoperative planning, a full-length weight-bearing X-ray photograph of the lower limb was opened within Adobe Photoshop Software, and a targeted corrective mechanical axis line of the lower limb and its intersecting point at the lateral tibial plateau surface was drawn using rectangle selection and filling tools. A frame, which encircled the tibia and fibula, was created around the predicted osteotomy plane and then rotated until the ankle center was on the targeted mechanical axis line. Subsequently, a distal femoral condyle line and a proximal fibula axis line were drawn, and the angle between the two lines was measured and defined as the femurofibular angle (FFA). During biplane OWHTO, the preoperatively determined FFA was used to complete the correction of the mechanical axis. During follow-up, the postoperative mechanical weight-bearing line (WBL) of the lower limb, the mechanical femorotibial angle (mFTA), and the FFA were measured and compared with the preoperatively determined values. RESULTS: The mechanical WBL shifted from a preoperative value of 25.36 ± 5.02% to a postoperative value of 56.19 ± 0.10% from the medial border along the mediolateral width of the tibial plateau, and it was 56.57 ± 0.08% at the final follow-up (P < 0.01). The preoperatively determined value was 56.25%, and no significant difference was found compared with postoperative week-one and final follow-up values (P > 0.05). The mFTA was corrected from a preoperative varus of 4.02 ± 0.63° to a postoperative week-one valgus of 2.37 ± 0.28°, and it had a valgus of 2.48 ± 0.39° at the final follow-up (P < 0.01). No significant difference in the valgus was found compared with the postoperative week-one, final follow-up and preoperatively determined valgus of 2.34 ± 0.26° (P > 0.05). The postoperative week-one and final follow-up FFAs were 90.34 ± 1.53° and 90.33 ± 1.52°, respectively, and no significant difference was found compared with the preoperatively determined value of 90.12 ± 1.72° and the intraoperative setting value of 90.25 ± 1.67° (P > 0.05). All corrected values were within the acceptable range of preoperative planning. CONCLUSION: Preoperative planning of the FFA may be useful in OWHTO for patients with mild medial knee OA. Satisfactory correction of the postoperative targeted mechanical axis line of the lower limb can be obtained.

Inhibitory properties of Chinese Herbal Formula SanHuang decoction on biofilm formation by antibiotic-resistant Staphylococcal strains.

The aim of this study was to explore the effect of Chinese herbal SanHuang decoction (SH) on biofilm formation of antibiotic-resistant Staphylococci on titanium surface, and to explore its mechanism. Biofilm-forming ATCC 35984, ATCC 43300 and MRSE 287 were used in this study. The MICs of SH and vancomycin against Staphylococci were determined by the broth microdilution method. Six groups were designed, namely control group (bacteria cultured with medium), 1/8MIC SH group (1MIC SH was diluted by 1/8 using TSB or saline), 1/4MIC SH group, 1/2MIC SH group, 1MIC SH group and vancomycin group (bacteria cultured with 1MIC vancomycin). The inhibitory effect on bacterial adhesion and biofilm formation were observed by the spread plate method, CV staining, SEM, and CLSM. Real-time PCR was performed to determine the effect of SH on the expression levels of ica AD and ica R gene in ATCC 35984 during the biofilm formation. The strains were found to be susceptible to SH and vancomycin with MIC of 38.75 mg/ml and 2.5 µg/ml, respectively. SH with 1 MIC and 1/2 MIC could inhibit the bacteria adhesion, showing only scattered adhesion from SEM. CLSM showed that SH with 1 MIC and 1/2 MIC inhibited the biofilm formation. The quantitative results of the spread plate method and CV staining showed that there was significant differences between the SH groups (P < 0.05). Further, with an increase in SH concentration, the inhibitory effect became more obvious when compared with control group. Among the groups, vancomycin had the strongest inhibitory effect on bacterial adhesion and biofilm formation (P < 0.01). With an increase in SH concentration, the expression levels of ica AD decreased, and the expression of ica R increased correspondingly (P < 0.05). In conclusions, SH can inhibit the biofilm formation of antibiotic-resistant Staphylococci. Its probable mechanistic activity may be through the inhibition of polysaccharide intercellular adhesin synthesis by down-regulating the expression of ica AD gene.

[Short-term effectiveness of arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon for posterior cruciate ligament injuries].

OBJECTIVE: To investigate the short-term effectiveness of arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon for posterior cruciate ligament (PCL) injuries. METHODS: A clinical data of 30 patients with PCL injury, who were admitted between December 2015 and September 2018 and met the selection criteria, was retrospectively analyzed. All patients were treated with arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon and TightRope technique. Among them, 19 were male and 11 were female, aged 17-48 years (mean, 28.2 years). The PCL injury was caused by traffic accident in 8 cases, sport in 14 cases, falling and bruising by a heavy objective in 5 cases, and other injuries in 3 cases. The interval between injury and operation was 10-90 days (mean, 39.3 days). The PCL injury was rated as grade Ⅱ in 6 cases and grade Ⅲ in 24 cases. The posterior drawer test was positive in 26 cases and the inverse Lachman test was positive in 24 cases. The International Knee Documentation Committee (IKDC) score was 61.37±8.49, and the objective IKDC ligament grading was near normal in 2 cases, abnormal in 8 cases, and significantly abnormal in 20 cases. The modified Lysholm knee score was 62.20±5.67. The knee range of motion (ROM) was (101.83±8.15) °. RESULTS: The operative time ranged from 70 to 110 minutes (mean, 79.7 minutes). All incisions healed by first intetion. All patients were followed up 12-24 months (mean, 19.0 months). There were 3 cases of deep vein thrombosis in the lower extremity after operation, and 1 case of approximately 10° limitation of knee extension. At last follow-up, the posterior drawer test was positive in 2 cases and the inverse Lachman test was positive in 1 case, with significant differences compared with the preoperative period ( χ 2=38.571, P=0.000; χ 2=36.274, P=0.000). The IKDC score was 84.67±3.67, and the objective IKDC ligament grading was normal in 16 cases, nearly normal in 10 cases, abnormal in 3 cases, and significantly abnormal in 1 case; the modified Lysholm knee score was 90.37±4.49; all of the above indexes were significantly better than preoperative ones, and the differences were significant ( t=-12.387, P=0.000; Z=-2.810, P=0.005; t=-22.865, P=0.000). Knee ROM was (88.33±9.86)° at 1 month after operation and reached (113.33±13.48)° at last follow-up, showing significant differences between pre- and post-operation ( P<0.05). MRI re-examination showed that the form and position of reconstructed PCL were satisfactory. CONCLUSION: It can obtain good short-term effectiveness for PCL injuries by arthroscopic single bundle four-strand reconstruction using autologous semitendinosus tendon and anterior half of peroneus longus tendon, which has the advantages of reliable surgical approach, safe operation, and precise effectiveness.