Biomimetic nanocarriers loaded with temozolomide by cloaking brain-targeting peptides for targeting drug delivery system to promote anticancer effects in glioblastoma cells.

Glioma is the leading cancer of the central nervous system (CNS). The efficacy of glioma treatment is significantly hindered by the presence of the blood-brain barrier (BBB) and blood-brain tumour barrier (BBTB), which prevent most drugs from entering the brain and tumours. Hence, we established a novel drug delivery nanosystem of brain tumour-targeting that could self-assemble the method using an amphiphilic Zein protein isolated from corn. Zein's amphiphilicity prompted it to self-assembled into NPs, efficiently containing TMZ. This allowed us to investigate temozolomide (TMZ) for glioblastoma (GBM) treatment. To construct TMZ-encapsulated NPs (TMZ@RVG-Zein NPs), the NPs' Zein was clocked to rabies virus glycoprotein 29 (RVG29). To verify that the NPs could penetrate the BBB and precisely target and kill the GBM cancer cell line, in vitro studies were performed. The process of NPs penetrating cancer cell membranes was investigated using enzyme-linked immunosorbent assays (ELISAs) to measure the expressions of nicotinic acetylcholine receptors (nAChRs) on the U87 cell line. Therefore, effective targeted brain cancer treatment is possible by forming NP clocks, a cell-penetrating natural Zein protein with an RVG29. These NPs can penetrate the blood-brain barrier (BBB) and enter the glioblastoma (U87) cell line to release TMZ. These NPs have a distinct cocktail of biocompatibility and brain-targeting abilities, making them ideal for involving brain diseases.

Injectable Magnetic Hydrogel Filler for Synergistic Bone Tumor Hyperthermia Chemotherapy.

The therapeutic efficacy of bone tumor treatment is primarily limited by inadequate tumor resection, resulting in recurrence and metastasis, as well as the deep location of tumors. Herein, an injectable doxorubicin (DOX)-loaded magnetic alginate hydrogel (DOX@MAH) was developed to evaluate the efficacy of an alternating magnetic field (AMF)-responsive, chemothermal synergistic therapy for multimodality treatment of bone tumors. The prepared hydrogel exhibits a superior drug-loading capacity and a continuous DOX release. This multifunctionality can be attributed to the combined use of DOX for chemotherapy and iron oxide nanoparticle-containing alginate hydrogels as magnetic hyperthermia agents to generate hyperthermia for tumor elimination without the limit on penetration depth. Moreover, the hydrogel can be formed when in contact with the calcium ions, which are abundant in bone tissues; therefore, this hydrogel could perfectly fit the bone defects caused by the surgical removal of the bone tumor tissue, and the hydrogel could tightly attach the surgical margin of the bone to realize a high efficacy residual tumor tissue elimination treated by chemothermal synergistic therapy. The hydrogel demonstrates excellent hyperthermia performance, as evidenced by in vitro cytotoxicity tests on tumor cells. These tests reveal that the combined therapy based on DOX@MAH under AMF significantly induces cell death compared to single magnetic hyperthermia or chemotherapy. In vivo antitumor effects in tumor-bearing mice demonstrate that DOX@MAH injection at the tumor site effectively inhibits tumor growth and leads to tumor necrosis. This work not only establishes an effective DOX@MAH system as a synergistic chemothermal therapy platform for treating bone tumors but also sheds light on the application of alginate to combine calcium ions of the bone to treat bone defect diseases.

Multi-needle blow-spinning technique for fabricating collagen nanofibrous nerve guidance conduit with scalable productivity and high performance.

Nerve guidance conduits (NGCs) have been widely accepted as a promising strategy for peripheral nerve regeneration. Fabricating ideal NGCs with good biocompatibility, biodegradability, permeability, appropriate mechanical properties (space maintenance, suturing performance, etc.), and oriented topographic cues is still current research focus. From the perspective of translation, the technique stability and scalability are also an important consideration for industrial production. Recently, blow-spinning technique shows great potentials in nanofibrous scaffolds fabrication, possessing high quality, high fiber production rates, low cost, ease of maintenance, and high reliability. In this study, we proposed for the first time the preparation of a novel NGC via blow-spinning technique to obtain optimized performances and high productivity. A new collagen nanofibrous neuro-tube with the bilayered design was developed, incorporating inner oriented and outer random topographical cues. The bilayer structure enhances the mechanical properties of the conduit in dry and wet, displaying good radial support and suturing performance. The porous nature of the blow-spun collagen membrane enables good nutrient delivery and metabolism. The in vitro and in vivo evaluations indicated the bilayer-structure conduit could promoted Schwann cells growth, neurotrophic factors secretion, and axonal regeneration and motor functional recovery in rat.

Implementation of a Virtual Reality Based Digital-Twin Robotic Minimally Invasive Surgery Simulator.

The rapid development of computers and robots has seen robotic minimally invasive surgery (RMIS) gradually enter the public's vision. RMIS can effectively eliminate the hand vibrations of surgeons and further reduce wounds and bleeding. However, suitable RMIS and virtual reality-based digital-twin surgery trainers are still in the early stages of development. Extensive training is required for surgeons to adapt to different operating modes compared to traditional MIS. A virtual-reality-based digital-twin robotic minimally invasive surgery (VRDT-RMIS) simulator was developed in this study, and its effectiveness was introduced. Twenty-five volunteers were divided into two groups for the experiment, the Expert Group and the Novice Group. The use of the VRDT-RMIS simulator for face, content, and structural validation training, including the peg transfer module and the soft tissue cutting module, was evaluated. Through subjective and objective evaluations, the potential roles of vision and haptics in robot surgery training were explored. The simulator can effectively distinguish surgical skill proficiency between experts and novices.

A Comparative Study of Antitumor Immunity Induced by Radiofrequency Microwave and Cryoablation in Hepatocellular Carcinoma.

PURPOSE: This study aimed to compare the immune responses induced by microwave ablation (MWA), radiofrequency ablation (RFA), and cryoablation (CRYO) in hepatocellular carcinoma (HCC) and identify differences in immune responses and the timing of immune changes. MATERIALS AND METHODS: A bilateral subcutaneous model was established in C57 mice, and the successfully modeled mice were divided into the microwave (n = 15), radiofrequency (n = 15), CRYO (n = 15), control (n = 9), and blank groups (n = 3). Mice in the control group were dissected before ablation, whereas mice in the three ablation groups underwent ultrasound-guided ablation of one axillary tumor. Three mice were sacrificed and dissected at 1-4 weeks after ablation. After tissue processing, flow cytometry was used to detect the levels of CD8 + T and regulatory T (Treg) cells in the tissue, and western blotting was used to assess the level of programmed cell death ligand 1 (PD-L1) protein in the tumor tissue. RESULTS: The pattern of immune changes after the three types of ablation was consistent, with immune changes occurring at 3-4 weeks. CRYO induced the most significant increase in the percentage of CD8 + T cells. There were no significant differences in the levels of Treg cells and the level of PD-L1 protein among the three types of ablation (p > 0.05), but the decline in Treg cells and PD-L1 protein level caused by CRYO was the most pronounced. CONCLUSION: In the HCC mouse model, the immune changes following the three types of ablation were consistent, with immune changes occurring at 3-4 weeks. Among them, CRYO elicited the strongest adaptive immune response, and RFA outperformed MWA.

Three-dimensional template combined with MR-guided iodine-125 brachytherapy for recurrent brain metastases.

Purpose: Treatment of recurrent brain metastases is extremely challenging. Here, we evaluated the feasibility and efficacy of an individualized three-dimensional template combined with MR-guided iodine-125 (125I) brachytherapy in the treatment of recurrent brain metastases. Material and methods: Twenty-eight patients with recurrent 38 brain metastases underwent 125I brachytherapy from December, 2017 to January, 2021. A pre-treatment brachytherapy plan and three-dimensional template were generated according to isovoxel T1-weighted MR images. 125I seeds were implanted under the guidance of three-dimensional template and 1.0-T open MR imaging. Dosimetry verification was performed based on CT/MR fusion images. Pre-operative and post-operative dosimetry parameters of D90, V100, and conformity index (CI) were compared. Overall response rate (ORR), disease control rate (DCR) at 6 months, and 1-year survival rate were calculated. Median overall survival (OS) measured from the date of 125I brachytherapy was estimated using Kaplan-Meier method. Results: No significant differences were observed between pre-operative and post-operative D90, V100, and CI values (p > 0.05). The ORR and DCR at 6 months were 91.3% and 95.7%, respectively. The 1-year survival rate was 57.1%. The median OS was 14.1 months. Two cases of minor hemorrhage and 5 cases of symptomatic brain edema were observed during the study. All clinical symptoms were alleviated after corticosteroid treatment applied for 7 to 14 days. Conclusions: A three-dimensional template combined with MR-guided 125I brachytherapy in the treatment of recurrent brain metastases is feasible, safe, and effective. This novel 125I brachytherapy strategy is an attractive alternative in the treatment of brain metastases.

A multifaceted biomimetic periosteum with a lamellar architecture and osteogenic/angiogenic dual bioactivities.

An artificial periosteum has emerged as an encouraging candidate for bone defect repair. Currently, it remains a great challenge to develop a multifaceted biomimetic periosteum integrating multifunctional features of bioactivities and unique mechanical properties. Here, we successfully fabricated an artificial periosteum (AP) composed of hierarchically assembled Mg-doped mineralized collagen microfibrils with a biomimetically rotated lamellar structure via a "multiscale cascade regulation" strategy combining multiple techniques such as molecular self-assembly, electrospinning, and pressure-driven fusion from molecular to macroscopic levels. The AP has excellent mechanical properties with an ultimate strength and a tensile modulus of 15.9 MPa and 1.1 GPa, respectively. The involvement of Mg-doped nano-hydroxyapatite endowed the AP with good osteogenic and angiogenic activities to promote osteogenic differentiation of bone marrow mesenchymal stem cells and human umbilical vein endothelial cell differentiation into capillary-like structures in vitro. In addition, the results of in vivo evaluations in a rat cranial bone defect model including micro-CT morphology, histological staining, and immunohistochemical analysis showed that Mg-doped mineralized collagen-based AP (MgMC@AP) significantly facilitated cranial bone regeneration and fast vascularization. Our findings suggest that the AP mimicked the composition, lamellar structure, mechanical properties, and biological activities of natural periosteum/lamellae, showing great promise for bone tissue regeneration.

Construction of a mineralized collagen nerve conduit for peripheral nerve injury repair.

A new nerve guidance conduits (NGCs) named MC@Col containing Type I collagen (Col) and mineralized collagen (MC) was developed, enhancing mechanical and degradation behavior. The physicochemical properties, the mechanical properties and in vitro degradation behavior were all evaluated. The adhesion and proliferation of Schwann cells (SCs) were observed. In the in vivo experiment, MC@Col NGC and other conduits including Col, chitosan (CST) and polycaprolactone (PCL) conduit were implanted to repair a 10-mm-long Sprague-Dawley rat's sciatic nerve defect. Histological analyses, morphological analyses, electrophysiological analyses and further gait analyses were all evaluated after implantation in 12 weeks. The strength and degradation performance of the MC@Col NGC were improved by the addition of MC in comparison with pure Col NGC. In vitro cytocompatibility evaluation revealed that the SCs had good viability, attachment and proliferation in the MC@Col. In in vivo results, the regenerative outcomes of MC@Col NGC were close to those by an autologous nerve graft in some respects, but superior to those by Col, CST and PCL conduits. The MC@Col NGC exhibited good mechanical performance as well as biocompatibility to bridge nerve gap and guide nerve regeneration, thus showing great promising potential as a new type of conduit in clinical applications.

Exercise intervention mitigates zebrafish age-related sarcopenia via alleviating mitochondrial dysfunction.

Sarcopenia is a common disorder that leads to a progressive decrease in skeletal muscle function in elderly people. Exercise effectively prevents or delays the onset and progression of sarcopenia. However, the molecular mechanisms underlying how exercise intervention improves skeletal muscle atrophy remain unclear. In this study, we found that 21-month-old zebrafish had a decreased swimming ability, reduced muscle fibre cross-sectional area, unbalanced protein synthesis, and degradation, increased oxidative stress, and mitochondrial dysfunction, which suggests zebrafish are a valuable model for sarcopenia. Eight weeks of exercise intervention attenuated these pathological changes in sarcopenia zebrafish. Moreover, the effects of exercise on mitochondrial dysfunction were associated with the activation of the AMPK/SIRT1/PGC-1α axis and 15-PGDH downregulation. Our results reveal potential therapeutic targets and indicators to treat age-related sarcopenia using exercise intervention.

Cardioprotective responses to aerobic exercise-induced physiological hypertrophy in zebrafish heart.

Herein, we aimed to establish an aerobic exercise-induced physiological myocardial hypertrophy zebrafish (Danio rerio) model and to explore the underlying molecular mechanism. After 4 weeks of aerobic exercise, the AMR and Ucrit of the zebrafish increased and the hearts were enlarged, with thickened myocardium, an increased number of myofilament attachment points in the Z-line, and increased compaction of mitochondrial cristae. We also found that the mTOR signaling pathway, angiogenesis, mitochondrial fusion, and fission event, and mitochondrial autophagy were associated with the adaptive changes in the heart during training. In addition, the increased mRNA expression of genes related to fatty acid oxidation and antioxidation suggested that the switch of energy metabolism and the maintenance of mitochondrial homeostasis induced cardiac physiological changes. Therefore, the zebrafish heart physiological hypertrophy model constructed in this study can be helpful in investigating the cardioprotective mechanisms in response to aerobic exercise.

Chinese expert consensus of image-guided irreversible electroporation for pancreatic cancer.

Pancreatic cancer (PC) is a lethal disease with extremely high mortality. Although surgical resection is the optimal therapeutic approach for PC, about 30%-40% of those patients are not candidates for surgical resection when diagnosed. Chemotherapy and radiotherapy also could not claim a desirable effect on PC. The application of interventional radiology approaches is limited by unavoidable damage to the surrounding vessels or organs. By the superiority of mechanism and technology, IRE could ablate the tumor by creating irreversible pores on the membrane of PC cells with other tissues like vessels and pancreatic ducts untouched. This consensus gathers the theoretical basis and clinical experience from multiple Chinese medical centers, to provide the application principles and experience from Chinese experts in the IRE field.

[Retrograde muscle release method in treatment of mild to moderate ischemic muscle contracture of forearm].

OBJECTIVE: To investigate the effectiveness of retrograde muscle release in treatment of mild to moderate type ischemic muscle contracture of forearm classified by Tsuge. METHODS: Between March 2010 and September 2018, 11 patients with mild to moderate ischemic muscle contracture of forearm were treated with retrograde muscle release. There were 6 males and 5 females with an average age of 24 years (range, 16-29 years). According to Tsuge classification, 6 cases were mild type and 5 cases were moderate type. The interval between injury and operation was 9 months to 25 years, with a median of 17 years. The scar cords in the muscle of the middle one-third of the forearm was released firstly. If the standard of sufficient release was not reached, further releasing the scar cords in the muscle and the tense tendon structure in the proximal one-third of the forearm and the origins of the flexor muscles was necessary. If the standard was still not reached, the origins of the flexor muscles can be released and slid. The effectiveness was evaluated from six aspects of the range of motion of the hand and wrist, dexterity, grip strength, sensation, subjective function scores [quick-disability of the arm, shoulder, and hand questionnaire (Quick-DASH) and the patient-related wrist/hand evaluation (PRWHE)] and satisfaction. RESULTS: All the incisions healed by first intention. Eight patients were followed up 1-106 months (median, 13 months). The range of motion of the hand and wrist was significantly improved, the results were excellent in 3 cases, good in 3 cases, and fair in 2 cases, with an excellent and good rate of 75%. The patient's dexterity evaluation scored a perfect score of 12, which was close to the normal hand dexterity. At last follow-up, the grip strength on the affected side was 37.6%-95.5% of the contralateral side, with an average of 77.6%. Seven patients had normal sensation before and after operation, and the two-point discrimination of median nerve and ulnar nerve was 4-5 mm at last follow-up; 1 patient with forearm mechanical crush injury still felt numb after operation, and the two-point discrimination of median nerve and ulnar nerve was 8 mm and 7 mm, respectively. The Quick-DASH score was 0-15.9, with an average of 4.5, and the PRWHE score was 0-23.0, with an average of 6.6. All the patients were satisfied with the surgery and the effectiveness. CONCLUSION: A targeted retrograde muscle release method for mild to moderate type ischemic contracture of forearm can achieve satisfactory effectiveness.

Magnetic resonance-guided repeat biopsy of suspicious malignant lung lesions after an initial negative computed tomography-guided Biopsy.

Objective: This study sought to establish the diagnostic utility of performing a second biopsy using an magnetic resonance (MR)-guided percutaneous transthoracic needle biopsy (PTNB) approach in patients with suspicious malignant lung lesions that had already undergone an initial negative computed tomography (CT)-guided biopsy. Materials and Methods: This study evaluated 31 patients with suspicious lung lesions (18 males, 13 females; mean age: 62.1 ± 11.3 years) that had previously undergone CT-guided PTNB with negative pathological findings January 2015-November 2020. A final histopathological diagnosis was made based on resected lung lesion specimens or, when resection was not conducted, on clinical diagnosis following a ≥6-month follow-up. The diagnostic accuracy of MR-guided secondary lung biopsy was determined by comparing the lung biopsy results for each patient to their final diagnosis. Results: 1.0T open MR-guided secondary lung biopsy was performed for 31 lesions (20 central, 11 peripheral; mean size, 5.3 ± 2.0 cm). The pathological results revealed 20/31 (64.5%) lesions to be malignant (14 adenocarcinoma, 4 squamous cell carcinoma, and 2 small-cell lung cancer) as detected by 1.0T open MR-guided PTNB and confirmed by surgical pathology and clinical follow-up. There were three instances of biopsy-induced complications including hemorrhage in 6.5% of the patients (2/31) and pneumothorax in 3.2% of the patients (1/31). No patients experienced severe complications. Conclusion: For individuals with clinically suspicious lung lesions that initially received negative CT-guided PTNB findings, 1.0T open MR-guided secondary lung biopsy is a safe and effective secondary diagnostic approach.

Simultaneously distributed temperature and dynamic strain sensing based on a hybrid ultra-weak fiber grating array.

A fiber-optic sensing system based on two types of ultra-weak fiber Bragg gratings (UWFBG) for simultaneous temperature and vibration sensing was proposed. Narrowband and broadband UWFBGs are alternately written into an optical fiber with equal spacing. Distributed temperature sensing is realized by demodulating the wavelength shift of the narrowband UWFBG, while distributed vibration sensing is achieved by detecting phase variation between two adjacent broadband UWFBG interference pulses. The experimental results show that the proposed hybrid UWFBG array can perform temperature and vibration sensing simultaneously. The experimentally conducted temperature measurement ranges from 20°C to 100°C, with the measurement error less than 0.1°C. Vibration signals at different temperatures can be accurately restored, and the signal-to-noise ratio (SNR) is improved by 21.1 dB compared with a normal single-mode fiber (SMF).

Magnetic resonance-guided ablation of liver tumors: A systematic review and pooled analysis.

PURPOSE: The purpose of this study is to study the clinical outcomes of different types of magnetic resonance (MR)-guided ablation for the treatment of liver tumors by performing a systematic review and pooled analysis. MATERIALS AND METHODS: A comprehensive literature search was performed for clinical trials published from January 1997 to October 2019 in PubMed, the Web of Science, Embase, and the Cochrane Library. Pooled analyses were performed to obtain the complete ablation (CA), complication, progression-free survival (PFS), and overall survival (OS) rates. RESULTS: Thirty studies were eligible, including four studies on MR-guided microwave ablation (MWA); 14 studies on MR-guided radiofrequency ablation (RFA); one study on both MR-guided MWA and RFA; eight studies on MR-guided, laser-induced thermotherapy (LITT); two studies on MR-guided percutaneous cryoablation (PC); and one study on MR-guided percutaneous ethanol injection (PEI). The CA rates in patients who underwent RFA, MWA, LITT, PC, and PEI were 95.60%, 98.86%, 77.78%, 47.92%, and 85.71%, respectively. The most frequent complications were pain (27.66%, 13/47) and postablation syndrome (27.66%, 13/47) in the PC group; pleural effusion (8.11%, 119/1,468) and subcapsular hematoma (2.25%, 33/1,468) in the LITT group; pleural effusion (2.67%, 2/75) in the MWA group; and subcapsular hematoma (4.18%, 20/478) and post-ablation syndrome (2.93%, 14/478) in the RFA group. There were few studies reporting PFS and OS. CONCLUSIONS: MR-guided ablation is a practicable alternative treatment for liver tumors, especially MR-guided RFA and MWA, which have high rates of CA and low occurrences of complications.

A novel three-dimensional template combined with MR-guided 125I brachytherapy for recurrent glioblastoma.

BACKGROUND: At present, the treatment of recurrent glioblastoma is extremely challenging. In this study, we used a novel three-dimensional non-coplanar template (3DNPT) combined with open MR to guide 125I seed implantation for recurrent glioblastoma. The aim of this study was to evaluate the feasibility, accuracy, and effectiveness of this technique. METHODS: Twenty-four patients of recurrent glioblastoma underwent 3DNPT with open MR-guided 125I brachytherapy from August 2017 to January 2019. Preoperative treatment plan and 3DNPT were made according to enhanced isovoxel T1-weighted MR images. 125I seeds were implanted using 3DNPT and 1.0-T open MR imaging guidance. Dosimetry verification was performed after brachytherapy based on postoperative CT/MR fusion images. Preoperative and postoperative dosimetry parameters of D90, V100, V200, conformity index (CI), external index (EI) were compared. The objective response rate (ORR) at 6 months and 1-year survival rate were calculated. Median overall survival (OS) measured from the date of brachytherapy was estimated by Kaplan-Meier method. RESULTS: There were no significant differences between preoperative and postoperative dosimetry parameters of D90, V100, V200, CI, EI (P > 0.05). The ORR at 6 months was 75.0%. The 1-year survival rate was 58.3%. Median OS was 12.9 months. One case of small amount of epidural hemorrhage occurred during the procedure. There were 3 cases of symptomatic brain edema after brachytherapy treatment, including grade three toxicity in 1 case and grade two toxicity in 2 cases. The three patients were treated with corticosteroid for 2 to 4 weeks. The clinical symptoms related to brain edema were significantly alleviated thereafter. CONCLUSIONS: 3DNPT combined with open MR-guided 125I brachytherapy for circumscribed recurrent glioblastoma is feasible, effective, and with low risk of complications. Postoperative dosimetry matched the preoperative treatment plan. The described method can be used as a novel implantation technique for 125I brachytherapy in the treatment of recurrent gliomas. TRIAL REGISTRATION: The study was approved by the Institutional Review Board of Shandong Provincial Hospital Affiliated to Shandong University (NSFC:NO.2017-058), registered 1st July 2017.

Clinical Application of Percutaneous Transforaminal Endoscopic Surgery in Lumbar Discal Cyst.

BACKGROUND: Discal cyst is very rare and can cause intractable low back pain and radiating leg pain. Symptoms are hard to distinguish from lumbar disc herniation. The best treatment for discal cyst is controversial. Most lumbar discal cysts are treated surgically, while most studies of percutaneous transforaminal endoscopic surgery are case reports. This study investigated the clinical value of percutaneous transforaminal endoscopic surgery for lumbar discal cyst. METHODS: A retrospective study was conducted in 9 patients with a discal cyst from June 2016 to November 2018. All patients had been treated by percutaneous transforaminal endoscopic surgery via a superior vertebral pedicle notch approach. Surgical outcomes were evaluated preoperatively and postoperatively using a visual analog scale for leg pain and the Oswestry Disability Index. At the final follow-up, patients were evaluated for clinical efficacy using modified Macnab criteria. RESULTS: All 9 patients had remission of symptoms after removal of discal cysts. Postoperative magnetic resonance imaging showed that all patients had complete excision of discal cysts and complete decompression of the treated segment. There were no recurrent lesions during follow-up. Mean operative time was 68.67 ± 14.02 minutes. Mean hospitalization time was 4.22 ± 1.64 days. Preoperative visual analog scale and Oswestry Disability Index score improved significantly after surgery. Visual analog scale leg score improved from 7.88 ± 1.05 preoperatively to 1.78 ± 0.66 at final follow-up (P < 0.05), and ODI score improved from 53.65 ± 12.46 to 16.25 ± 8.76 (P < 0.05). According to the modified Macnab criteria, 5 patients (55.6%) were rated excellent, 3 patients (33.3%) were rated good, and 1 patient (11.1%) was rated fair at final follow-up, with an overall excellent and good rate of 88.9%. There were no serious complications during follow-up. CONCLUSIONS: Percutaneous transforaminal endoscopic surgery could be a safe, minimally invasive surgical treatment for discal cyst, particularly suitable for patients who cannot undergo general anesthesia.

Relative Permeability Characteristics During Carbon Capture and Sequestration Process in Low-Permeable Reservoirs.

The injection of carbon dioxide (CO2) in low-permeable reservoirs can not only mitigate the greenhouse effect on the environment, but also enhance oil and gas recovery (EOR). For numerical simulation work of this process, relative permeability can help predict the capacity for the flow of CO2 throughout the life of the reservoir, and reflect the changes induced by the injected CO2. In this paper, the experimental methods and empirical correlations to determine relative permeability are reviewed and discussed. Specifically, for a low-permeable reservoir in China, a core displacement experiment is performed for both natural and artificial low-permeable cores to study the relative permeability characteristics. The results show that for immiscible CO2 flooding, when considering the threshold pressure and gas slippage, the relative permeability decreases to some extent, and the relative permeability of oil/water does not reduce as much as that of CO2. In miscible flooding, the curves have different shapes for cores with a different permeability. By comparing the relative permeability curves under immiscible and miscible CO2 flooding, it is found that the two-phase span of miscible flooding is wider, and the relative permeability at the gas endpoint becomes larger.

Multiparametric magnetic resonance-guided and monitored microwave ablation in liver cancer.

PURPOSE: The objective of our study was to prospectively evaluate the feasibility, effectiveness, and safety of 1.0T open multiparametric magnetic resonance (MR)-guided and monitored microwave ablation (MWA) of liver cancer. MATERIALS AND METHODS: Fifty-six liver lesions (12 - initial hepatocellular carcinoma, 34 - recurrent hepatocellular carcinoma, and 10 - metastatic liver cancers) in 45 patients were treated with MWA ablation using MR guidance and monitoring. The mean diameter of the liver lesions was 1.7 ± 0.9 cm (range, 0.5-4.6 cm). The 56 liver lesions were divided into 3 groups according to diameter: the <1.0 cm group (17 lesions), the 1.0-2.0 cm group (19 lesions), and the >2.0 cm group (20 lesions). Technical success, technical effectiveness, local tumor progression, procedure duration, and complications were assessed. Primary technical effectiveness was assessed 3 months after the MWA, while local tumor progression was assessed more than 3 months after the MWA. The follow-up time for assessment of treatment response ranged from 12 to 30 months (median, 23 months). RESULTS: The technical success rate was 100%. Primary technical effectiveness was achieved in 52/56 (92.8%) lesions. Local tumor progression was detected in three tumors after initial technical effectiveness. The median duration of the intervention per tumor was 66 min (range, 40-156 min). There were no significant differences between lesion groups in the technical success rate, primary technical effectiveness rate, or local tumor progression rate. There were no major complications following the ablation therapy. CONCLUSIONS: 1.0T open multiparametric MR-guided and MR-monitored MWA for liver cancer is safe and feasible and decreases the risk of local tumor progression; it also provides good primary technique effectiveness rates and is especially suitable when ultrasound and CT facilitated treatments are inappropriate.

Clinical application of large channel endoscopic decompression in posterior cervical spine disorders.

BACKGROUND: We investigated the clinical value of posterior percutaneous endoscopic decompression (PED) for single-segment cervical spondylotic myelopathy (CSM) and cervical spondylotic radiculopathy (CSR). METHODS: Clinical data from February 2016 to March 2018 were collected for 32 patients with single-segment CSM or CSR who underwent posterior cervical percutaneous large channel endoscopic decompression and completed a regular follow-up exam at 12 months after surgery. Patient data included: age (range 30-81 years and mean of 49.5 years) and surgical information (operation time, bleeding volume, hospital stay, complications, etc.). The Japan Orthopedic Association (JOA) score and pain visual analog scale (VAS) were used to evaluate the surgical outcome for each patient. Cervical spine radiographs were used to evaluate cervical curvature (Cervical spondylotic angle (CSA), C2-7 Cobb angle) and CT and MRI were used to assess the extent of laminectomy and nerve root decompression. The JOA score, VAS score, cervical curvature were analyzed statistically, and the clinical outcome was evaluated using modified Macnab criteria at the last patient follow-up exam. RESULTS: The JOA and VAS scores were compared before and after surgery (1 day Pre-op; 3 days, 3 months and 12 months Post-op). The differences were statistically significant (P < 0.05). There were significant differences in cervical curvature (C2-7 Cobb angle) between the time points (1 day Pre-op; 3 days, 3 months and 12 months Post-op), but the differences were no statistically significant in CSA angle (P < 0.05) The operation time range was 45-110 min (mean 68.6 ± 23.8 min); the intraoperative blood loss range was 20-85 ml (mean28 ± 14.8 ml), and the hospital stay was 3-8 days (mean4.5 days). At the last follow-up, the clinical efficacy was evaluated using modified Macnab criteria. The results were excellent in 18 cases, good in 11 cases, and fair in 3 cases. The combined excellent and good rate was 93.75%. Postoperative CT and MRI showed that the compression of the spinal cord or nerve roots was completely relieved. CONCLUSION: Endoscopic decompression of posterior cervical vertebral disorders is a safe, effective, and minimally invasive surgical procedure with rapid recovery times. This procedure warrants additional research and clinical application.