Recycling Pomelo Peel Waste in the Form of Hydrochar Obtained by Microwave-Assisted Hydrothermal Carbonization.

Pomelo peel (PP) is a kind of solid waste that is produced in the processing industry of honey pomelo. This study deeply explored the feasibility of recycling PP in the form of hydrochar (HC) by microwave-assisted hydrothermal carbonization (HTC) technology. Under the non-catalytic reaction conditions, the yield of hydrochar initially increased with the rise of reaction temperature (150-210 °C) until it remained relatively stable after 210 °C. Under the CaO-catalytical reaction condition, the yield of hydrochar did not change much at first (150-190 °C) but decreased significantly when the reaction temperature exceeded 190 °C. After the microwave-assisted HTC treatment, the PP-derived HC presented higher aromaticity, carbonization degree, porosity, and caloric value. Compared with raw PP, the nutrients in HC were more stable (conducive to being used as slow-release fertilizer). The application of CaO increased the pH value of HC and effectively promoted the accumulation of phosphorus in HC. The HC produced at 210 °C without any catalyst possessing a high devolatilization ability. Additionally, the HC obtained at 190 °C with CaO as the catalyst presented a high combustion property. In general, PP-derived HC showed great application potential in the field of soil remediation/improvement and solid fuels. This preliminary study would undoubtedly provide some important fundamental understanding of the microwave-assisted HTC of PP.

Efficient conversion of sewage sludge into hydrochar by microwave-assisted hydrothermal carbonization.

The treatment of sewage sludge (SS) is an environmental problem worldwide. In recent years, hydrothermal carbonization (HTC) of SS for hydrochar (HC) has attracted extensive attention. This study preliminarily explored the microwave-assisted HTC of SS for the first time. Increasing the reaction temperature (150-250 °C) and reaction time (0-120 min) resulted in a decrease in the HC yield, and it gradually increased with the rising solid-liquid ratio (0.03-0.25 g/mL). Compared with raw SS, the HC products possessed higher aromaticity, carbonization degree, porosity, and polarity, and lower content of soluble nutrients (N/P/K) and leachable heavy metals (Cu, Zn, Pb, Cd, Cr, and Ni), indicating a lower risk of nutrient and heavy metal loss. Attention should be paid to the total contents of Zn and Cd in HC exceeded the permitted value for use in cultivated land with edible crops. The use of CaO as a catalyst improved the yield of HC, made the HC and process water (PW) weakly alkaline, and further passivated the heavy metals in the HC. In the case of H3PO4, although the conversion of SS was enhanced (lower content of volatile organic matter in HC), the contents of soluble nutrients (N/P/K) in HC/PW increased, and the migration of Zn and Cd into process water was enhanced. The HCs obtained in this study had poor combustion properties, but higher ignition temperatures than raw SS. PW must be properly treated or recycled because it still contained high contents of organic matter and nutrients. This fundamental study provides basic insights into the microwave-assisted HTC of SS.

Effects of rice straw/wood sawdust addition on the transport/conversion behaviors of heavy metals during the liquefaction of sewage sludge.

Lignocellulosic biomass has been widely introduced into the liquefaction process of sewage sludge (SS) to improve the yield/quality of liquefaction products (bio-oil/biochar). This study explores the effect of adding rice straw (RS) and wood sawdust (WS) on the transport/conversion behaviors of heavy metals (HMs) during the liquefaction of SS. The introduction of lignocellulosic biomass, especially for RS, substantially lowers the total content of HMs in biochar. Most HMs (except Cd) still remain in biochar, although the introduction of RS/WS enhances the transport of HMs into bio-oils. The addition of RS/WS raises the percentage of HMs in active form, but the contents of bioavailable/leachable HMs are not considerably increased and even decreased in some cases, especially when RS is introduced. The overall pollution degree and environmental risk of HMs in biochars are lowered to a certain extent with the addition of RS/WS. Considering that the pollution degree and environmental risk of HMs present in biochars are still at a considerable level, appropriate pollution management measures should be undertaken when using such biochars for agricultural use.

Laparoscopic Acetabular Fracture Fixation after Three-dimensional Modelling and Printing.

Current surgical treatment of acetabular fractures is open reduction and internal fixation and requires a large incision resulting in considerable blood loss and a potentially long duration of recovery. We report a case of an acetabular fracture that received laparoscopic internal fixation after three-dimensional (3D) modelling and printing of the acetabulum. A 43 year old male fell from a height of 3 m resulting in a right acetabulum anterior column fracture. Thin section computed tomography scanning with 0.6 mm increments and subsequent 3D reconstruction was performed, and a 3D model of the acetabulum and fracture was printed. The steel reconstruction plate was prebent in vivo and placed into the optimized position based on the 3D modelling and the optimized insert orientation and measured screw length were determined. The fracture was reduced and the plate placed laparoscopically without complications, and the patient had excellent functional recovery. Acetabular fractures are complex injuries, and while minimally invasive surgical techniques are used in many fields, they are not common for the treatment of acetabular fractures. 3D modelling is commonly used in medicine, and although 3D printing is used in some fields, it has not found widespread use in orthopedics.

[Application of 3D printing and computer-assisted surgical simulation in preoperative planning for acetabular fracture].

OBJECTIVE: To evaluate the feasibility and effectiveness of using 3D printing and computer-assisted surgical simulation in preoperative planning for acetabular fractures. METHODS: A retrospective analysis was performed in 53 patients with pelvic fracture, who underwent surgical treatment between September, 2013 and December, 2015 with complete follow-up data. Among them, 19 patients were treated with CT three-dimensional reconstruction, computer-assisted virtual reset internal fixation, 3D model printing, and personalized surgery simulation before surgery (3D group), and 34 patients underwent routine preoperative examination (conventional group). The intraoperative blood loss, transfusion volume, times of intraoperative X-ray, operation time, Matta score and Merle D' Aubigne & Postel score were recorded in the 2 groups. Preoperative planning and postoperative outcomes in the two groups were compared. RESULTS: All the operations were completed successfully. In 3D group, significantly less intraoperative blood loss, transfusion volume, fewer times of X-ray, and shortened operation time were recorded compared with those in the conventional group (P<0.05). According to the Matta scores, excellent or good fracture reduction was achieved in 94.7% (18/19) of the patients in 3D group and in 82.4% (28/34) of the patients in conventional group; the rates of excellent and good hip function at the final follow-up were 89.5% (17/19) in the 3D group and 85.3% (29/34) in the conventional group (P>0.05). In the 3D group, the actual internal fixation well matched the preoperative design. CONCLUSIONS: 3D printing and computer-assisted surgical simulation for preoperative planning is feasible and accurate for management of acetabular fracture and can effectively improve the operation efficiency.

[Finite element modeling of material property assignment based on CT gray value and its application in simulation of osteotomy for deformities].

OBJECTIVE: To explore a new method for finite element modeling to achieve material property assignment based on in situ CT gray value in simulated osteotomies for deformities. METHODS: A CT scan dataset of the lower limb of a patient with extorsion deformity was obtained for three-dimensional reconstruction using Mimics software and preparing a solid model. In the CAD software, the parameters for osteotomy simulation were defined including the navigation axis, rotation angle and reference plane. The tibia model was imported to the FEA pre-processing software for meshing procedure and then exported to Mimics. All the segments of the tibia meshed model were assigned uneven material properties based on the relationship between CT gray values and material properties in the Mimics software. Finally, all the segments of the tibia model, reference axis and reference plane were assembled in the pre-processing software to form a full finite element model of a corrected tibia, which was submitted to resolver for biomechanical analysis. RESULTS: The tibia model established using our modeling method had inhomogeneous material properties based on CT gray values, and was available for finite element analysis for the simulation of osteotomy. CONCLUSIONS: The proposed finite element modeling method, which retains the accuracy of the material property assignment based on CT gray value, can solve the reposition problem commonly seen in modeling via the routine method of property assignment and provides an efficient, flexible and accurate computational biomechanical analysis method for orthopedic surgery.

[Clincial effect of 3D printing-assisted minimal invasive surgery through a small incision lateral to the rectus abdominis for pelvic fracture].

OBJECTIVE: To evaluate the clinical effect of 3D printing-assisted minimal invasive surgery on pelvic fracture by plate internal fixation through a small incision lateral to the rectus abdominis. METHODS: This retrospective study was conducted among 50 patients with pelvic fracture undergoing anteromedial plate internal fixation between September, 2013 and June, 2015. Thin-layer computed tomography scan data of the patients were input into Mimics software in DICOM format for 3D editing and virtual surgery before the operation. The pelvic model was created by 3D printing. Simulated operation was performed to design the optimum location of the plate screw, prelflex of the plate, screw length measurement and screwing approach. Diaplasis and internal fixation were performed through the extraperitoneal space with a small incision lateral to the rectus abdominis. Matta standard was employed for diaplasis evaluation, and Majeed assessment was used for function evaluation 6 months after the operation. RESULTS: According to Matta standard, excellent and good diaplases were achieved in 96% of the cases, as compared with 94% according to Majeed assessment. Radiographic examination showed a good consistency between the internal fixation and simulated operation. No screw entry into the hip joint cavity occurred in these cases. The mean operation time was 127 min in these cases with a mean intraoperative blood loss of 728 mL and a mean incision length of 8.4 cm. Based on the postoperative VAS score, 12 patients reported severe pain, 28 reported moderate pain and 10 reported mild pain. All the patients were advised for early functional exercise after the operation and clinical healing was achieved in a mean of 8 weeks. CONCLUSIONS: 3D printing with simulated operation can improve the accuracy and safety of the operation. Preoperative simulation of plate preflex and screw length measurement can shorten the operation time. A small incision lateral to the rectus abdominis allows minimally invasive operation for pelvic fractures.

The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

Various hydrothermal treatment methods, including hydrothermal carbonization, liquefaction and sub/super-critical water gasification, have been applied to the disposal of sewage sludge for producing bio-materials or bio-fuels. It has become a research hotspot whether the heavy metals contained in sewage sludge can be well treated/stabilized after the hydrothermal treatments. This review firstly summarized the methods of assessing heavy metals' contamination level/risk and then discussed the migration and transformation behaviors of heavy metals from the following aspects: the effect of reaction temperature, the effect of additives (catalysts and other biomass), the effect of the type of solvent and the effect of reaction time. This review can provide an important reference for the further study of the migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge.

[A Study of the Relationship Among Genetic Distances, NIR Spectra Distances, and NIR-Based Identification Model Performance of the Seeds of Maize Iinbred Lines].

This paper explored the relationship among genetic distances, NIR spectra distances and NIR-based identification model performance of the seeds of maize inbred lines. Using 3 groups (total 15 pairs) of maize inbred lines whose genetic distaches are different as experimental materials, we calculates the genetic distance between these seeds with SSR markers and uses Euclidean distance between distributed center points of maize NIR spectrum in the PCA space as the distances of NIR spectrum. BPR method is used to build identification model of inbred lines and the identification accuracy is used as a measure of model identification performance. The results showed that, the correlation of genetic distance and spectra distancesis 0.9868, and it has a correlation of 0.9110 with the identification accuracy, which is highly correlated. This means near-Infrared spectrum of seedscan reflect genetic relationship of maize inbred lines. The smaller the genetic distance, the smaller the distance of spectrum, the poorer ability of model to identify. In practical application, near infrared spectrum analysis technology has the potential to be used to analyze maize inbred genetic relations, contributing much to genetic breeding, identification of species, purity sorting and so on. What's more, when creating a NIR-based identification model, the impact of the maize inbred lines which have closer genetic relationship should be fully considered.

[Near infrared spectroscopy analysis method of maize hybrid seed purity discrimination].

Near infrared spectroscopy analysis method of discrimination of maize hybrid seed purity was studied with the sample of Nong Hua 101 (NH101) from different origins and years. Spectral acquisition time lasted for 10 months. Using Fourier transform (FT) near infrared spectroscopy instruments, including 23 days in different seasons (divided into five time periods), a total of 920 near infrared diffuse reflectance spectra of single corn grain of those samples were collected. Moving window average, first derivative and vector normalization were used to pretreat all original spectra, principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to reduce data dimensionality, and the discrimination model was established based on biomimetic pattern recognition (BPR) method. Spectral distortion was calibrated by spectra pretreatment, which makes characteristics spatial distribution range of sample spectra set contract. The relative distance between hybrid and female parent increased by nearly 70-fold, and the discrimination model achieved the identification of hybrid and female parent seeds. Through the choice of representative samples, the model's response capacity to the changes in spectral acquisition time, place and environment, etc. was improved. Besides, the model's response capacity to the changes in time and site of seed production was also improved, and the robustness of the model was enhanced. The average correct acceptance rate (CAR) of the test set reached more than 95% while the average correct rejection rate (CRR) of the test set also reached 85%.

[Study on the backward extraction of cellulase in rhamnolipid reverse micelles].

This paper studied the backward extraction of cellulase in RL/isooctane/n-hexanol reverse micelles system. Several key parameters influencing the backward extraction efficiency and activity recovery of cellulase were investigated, including stripping aqueous pH, stripping time, salt type and ionic strength, and addition of alcohols. The experiment results indicated that the optimal parameter values as follows: stripping aqueous pH 7.0, stripping time 30 min, 0.15 mol x L(-1) of KCl, dosage of n-butanol 2%. Under above optimum conditions, the backward extraction efficiency and activity recovery were up to 76.22% and 93.39%, respectively. The backward extraction of cellulase using reverse micelles based on biosurfactant RL performs well. Furthermore, RL has many advantages such as high biodegradability, low critical micelle concentration, etc. The application prospects of RL reverse micelles are extensive.

[Effect of endotracheal intubation and laryngeal mask airway on perioperative respiratory adverse events in children with upper airway infections].

OBJECTIVE: To investigate the effect of endotracheal intubation (TT) or the laryngeal mask airway (LMA) on the incidence of perioperative respiratory adverse events in children with upper respiratory tract infection undergo general anesthesia. METHODS: From November, 2006 to October, 2012 in the Zhuji People's Hospital, 76 children with upper respiratory tract infection approved by hospital ethic committee were randomly divided into 2 groups:group I (n = 36), children were applied with endotracheal intubation during general anesthesia (TT group), while groupII (n = 40), laryngeal mask airway were used (LMA group).Intraoperative mean arterial pressure (MAP), hear rate (HR), pulse oximetry (SPO2), and end-tidal carbon dioxide partial pressure (P ETCO2) were recorded during the surgery. The incidence of adverse events such as hypoxemia, fidgety, sore throat, and laryngospasm were evaluated in resuscitation room.We also assessed the pre- and postoperative symptoms of respiratory tract infection. RESULTS: There was no significant difference in upper respiratory tract infection symptoms between two groups, and the children in both groups have good tolerance to TT or LMA.However, the hemodynamics status in LMA group were more stable than those in TT group after the LMA insertion or removing (P < 0.05). The incidence of hypoxemia, fidgety, sore throat, and laryngospasm were significant lower in LMA group compared with those in TT group (P < 0.05). CONCLUSION: LMA could decrease the incidence of perioperative respiratory adverse events and can be safely used in children with upper respiratory tract infection undergo general anesthesia.

[Electricity generation of surplus sludge microbial fuel cells enhanced by additional enzyme].

In this paper the feasibility of enhanced electricity generation of microbial fuel cell fed surplus sludge by additional enzymes (neutral protease and alpha-amylase) was discussed. The effect of dosage of additional enzyme on characteristics of electricity generation of the surplus sludge microbial fuel cell (SSMFC) and the reduction of surplus sludge were investigated. The results indicated that the maximum output power destiny of the group of experiment was higher than that of control under the same condition. Moreover, the maximum output power density, coulomb efficiency, efficiency of reducing TCOD, efficiency of reducing TSS and efficiency of reducing VSS reached up to 507 W x m(-2) (700 mW x m(-2)), 3.98% (5.11%), 88.31% (94.09%), 83.18% (98.02%) and 89.03% (98.80%) respectively for protease (alpha-amylase) at the dosage of 10 mg x g(-1). This study demonstrated that additional enzyme greatly enhanced the electricity generation of MFC with simultaneous accomplishments of sludge treatment, providing a novel approach for the practical application of microbial fuel cell.

[Study on the bioleaching mechanism of manganse (II) from manganese-electrolytic residue by manganese-resistant strain Fusarium sp].

The manganse bioleaching mechanism by a manganese-resistant strain Fusarium sp. was investigated, through analyzing the bioleaching rate and manganese-electrolytic residue characterizations with the presence of Fusarium sp. and with the addition of organic acids. Special attention was paid to explore the relationship among the manganese's leaching rate, pH, and organic acid concentration during Fusarium sp. bioleaching process. The research results showed that, with the addition of Fusarium sp., some looser and more porous manganese-electrolytic residues could be obtained. And after 47 hours, the leaching rate reached to 84% which was 2.30 times higher than that leached by individual organic acid even after 130 hours; the leaching rate of manganese and the concentrations of organic acids increased at the initial stage and then decreased, while pH was the reversed. Additionally, the concentration of Succinic acid and L-Malic acid reached their crest value (11.12 g/L and 10.23 g/L) at 57 and 62 hours respectively. Yet the pH reached the lowest (4.09) at 29 h, which implied that, Fusarium sp. and organic acid produced played an important role in the leaching of manganese, leading to a high-efficiency and time-saving process. However, due to the high density of manganese-electrolytic residue and the concurrence of the produce and consumption of organic acid together with the adsorption and complexation, the relationship among the extraction rate for manganese ion, pH, and the concentration of organic acid produced could not be described by simple linear correlation and the leaching rate decreased significantly in the later stage.

[Effect of ozone water on the inflammation and repair in infected wounds].

OBJECTIVE: To study the effect of ozone water in promoting the healing of infected wounds. METHODS: Fifty Wistar rats were randomly divided into 5 groups, namely chlorhexidine treatment group, 5, 10, and 20 mg/L ozone water treatment groups, and the control group without any treatment. Infected wounds were induced on the back of the rats, and at 48 h of infection, chlorhexidine or ozone water was applied once daily for 9 days. Before and at days 3, 6, and 9 of the treatment, the wound changes were observed. The WBC in the tail venous blood was detected and the incised skin and muscular tissues were pathologically examined. RESULTS AMD CONCLUSION: Ozone water showed better effects in promoting the healing of the infected wound, especially at higher doses of 10 and 20 mg/L.