Pedicle drilling force control of a robotic surgical system via spine-soft tissue coupling model and parameters optimization.

Bone drilling is a crucial operation in spinal fusion surgery that requires precise control of the applied force to ensure surgical safety. This manuscript aims to enhance the force servo performance of the orthopedic robot during automatic bone drilling operations. Firstly, an analytical model is introduced to describe the spinal mobility of the spine-soft tissue coupling structure. Then, the model is calibrated using force data obtained from stress relaxation tests. Next, optimal force controller parameters are determined through drilling force control simulations based on the identified model. The dynamic performance and robustness of the closed-loop control system are analyzed to ensure safe drilling procedures. Finally, bone drilling experiments are conducted in a force control mode to verify the effectiveness of the proposed method. The step drilling force response's steady-state error is less than 0.15 N, the relative control error is less than 3 %, and there is no noticeable force overshoot. The amplitude of the sinusoidal force response decays to -3 dB when the target force frequency is up to 3.49 rad/s, indicating a wide control bandwidth. These results demonstrate that the proposed method can rapidly and safely provide an adequate force servo to carry out automatic bone drilling.

Identification of milling status based on vibration signals using artificial intelligence in robot-assisted cervical laminectomy.

BACKGROUND: With advances in science and technology, the application of artificial intelligence in medicine has significantly progressed. The purpose of this study is to explore whether the k-nearest neighbors (KNN) machine learning method can identify three milling states based on vibration signals: cancellous bone (CCB), ventral cortical bone (VCB), and penetration (PT) in robot-assisted cervical laminectomy. METHODS: Cervical laminectomies were performed on the cervical segments of eight pigs using a robot. First, the bilateral dorsal cortical bone and part of the CCB were milled with a 5 mm blade and then the bilateral laminae were milled to penetration with a 2 mm blade. During the milling process using the 2 mm blade, the vibration signals were collected by the acceleration sensor, and the harmonic components were extracted using fast Fourier transform. The feature vectors were constructed with vibration signal amplitudes of 0.5, 1.0, and 1.5 kHz and the KNN was then trained by the features vector to predict the milling states. RESULTS: The amplitudes of the vibration signals between VCB and PT were statistically different at 0.5, 1.0, and 1.5 kHz (P < 0.05), and the amplitudes of the vibration signals between CCB and VCB were significantly different at 0.5 and 1.5 kHz (P < 0.05). The KNN recognition success rates for the CCB, VCB, and PT were 92%, 98%, and 100%, respectively. A total of 6% and 2% of the CCB cases were identified as VCB and PT, respectively; 2% of VCB cases were identified as PT. CONCLUSIONS: The KNN can distinguish different milling states of a high-speed bur in robot-assisted cervical laminectomy based on vibration signals. This method is feasible for improving the safety of posterior cervical decompression surgery.

HSF1 inhibits microglia activation to attenuate neuroinflammation via regulating miR-214-3p and NFATc2 in Parkinson's disease.

Parkinson's disease (PD) is characterized by microglia activation that leads to neuroinflammation. Heat shock transcription factor 1 (HSF1) is known to exert neuroprotective effects on neurodegenerative diseases. This study sought to analyse the role and mechanism of HSF1 in PD-induced neuroinflammation. The PD mouse models were established using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Animal behaviour capacities and neuronal damage were assessed via behavioural tests, tyrosine hydroxylase (TH) staining, and immunofluorescence. Levels of HSF1, miR-214-3p, nuclear factor of activated T cells 2 (NFATc2), and neuroinflammatory factors were detected via RT-qPCR, Western blotting, and ELISA.Binding relationships between HSF1 and miR-214-3p, miR-214-3p, and NFATc2 were tested via dual-luciferase or chromatin immunoprecipitation assays. Functional rescue experiments were designed to confirm the roles of miR-214-3p and NFATc2. HSF1 expression in brain tissues was downregulated upon MPTP treatment. HSF1 overexpression reduced motor deficits and loss of dopaminergic neurons, increased TH-positive neurons, and repressed neuroinflammation and micro-glia activation. Mechanically, HSF1 bound to the miR-214-3p promoter to increase its expression and inhibited NFATc2 transcription. miR-214-3p downregulation or NFATc2 overexpression reversed the inhibition of HSF1 overexpression on neuroinflammation and microglia activation. Overall, our findings unveiled the therapeutic role of HSF1 in PD-induced neuroinflammation and microglia activation via regulating miR-214-3p and NFATc2.

Surgical Tool Handle Vibration-Based Drilling State Recognition During Hip Fracture Fixation.

OBJECTIVES: Traditional manual drilling during hip fracture fixation can easily lead to unstable fixation and vascular damage. This study aimed to investigate a safe and easy-to-use robot-assisted method to automatically drill bone and distinguish critical bone drilling states with high accuracy in real-time for the bone hole-making process during hip fracture fixation. METHODS: A bone-drilling robotic system was designed to automatically create holes in the femoral neck. Four fresh pig femurs were drilled at the posterosuperior femoral neck using three modes: "all-in" (AI), "in-out-in" (IOI), and "percutaneous fixation" (PF). A high-frequency accelerometer captured the generated vibrations of the drill handle, which were then transferred to a personal computer using a data acquisition card. Five bone drilling states are defined, including: "drill idling," "initial drilling," "in the cancellous bone," "out the femoral neck," and "in the cortical bone." The harmonic distribution of the vibration signal was extracted by fast Fourier transform (FFT) and used as a critical feature to identify different drilling states. To prove the difference in the harmonic distribution at different drilling states, an independent sample t-test was used to compare the percentage of the first harmonic amplitude in the first 10 harmonics at each drilling state. A neural network classifier was trained with the frequency spectrum as the input and the drilled state as the output to distinguish the critical bone drilling states with high accuracy in real-time. The classifier was trained and tested on four specimens to ensure that the surgical robot could accurately identify the five drilling states. RESULTS: In each specimen, the harmonic distributions of the drilling vibration at different drilling modes were significantly different (p < 0.05). The average recognition accuracies of the drilling state for the four specimens were all higher than 84%. The three defined modes were distinguished with extremely high accuracies. The recognition accuracies of "in the cancellous bone" for specimens 1 to 4 were 83.2%, 84.8%, 92.9%, and 84.7%. The recognition accuracies of "in out the femoral neck" from specimens 1 to 4 are 98.2%, 88.4%, 95.8%, and 88.8%. The recognition accuracies of "in the cortical bone" for specimens 1 to 4 were 94.6%, 80.8%, 95.5%, and 85.8%. CONCLUSIONS: The proposed robot-assisted method can automatically distinguish five critical bone-drilling states with high accuracy in real-time to avoid weak fixation and damage to the lateral epiphyseal artery.

Motor Bur Milling State Identification via Fast Fourier Transform Analyzing Sound Signal in Cervical Spine Posterior Decompression Surgery.

OBJECTIVES: To investigate the real-time sensitive feedback parameter of the motor bur milling state in cervical spine posterior decompression surgery, to possibly improve the safety of cervical spine posterior decompression and robot-assisted spinal surgeries. METHODS: In this study, the cervical spine of three healthy male and three healthy female pigs were randomly selected. Six porcine cervical spine specimens were fixed to the vibration isolation system. The milling state of the motor bur was defined as the lamina cancellous bone (CA), lamina ventral corticalbone (VCO), and penetrating ventral cortical bone (PVCO). A 5-mm bur milled the CA and VCO, and a 2-mm bur milled the VCO and PVCO. A miniature microphone was used to collect the sound signal (SS) of milling lamina which was then extracted using Fast Fourier Transform (FFT). When using 5-mm and 2-mm bur to mill, the CA, VCO, and PVCO of each specimen were continuously collected at 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 kHz frequencies for SS magnitudes. The study randomly selected the SS magnitudes of the CA and VCO continuously for 2 s at 1, 2, 3, 4, and 5 kHz frequencies for statistical analyses. When milling the VCO to the PVCO, we randomly collected the SS magnitudes of the VCO for consecutive 2 s and the SS magnitudes of continuous 2 s in the penetrating state at 1, 2, 3, 4, and 5 kHz frequencies for statistical analyses. The independent sample t-test was used to compare the SS magnitudes of different milling states extracted from the FFT to determine the motor bur milling state. RESULTS: The SS magnitudes of the CA and VCO of all specimens extracted from the FFT at 1, 2, and 3 kHz were statistically different (P < 0.01); three specimens were not statistically different at a specific FFT-extracted frequency (first specimen at 5 kHz, SS magnitudes of the CA were [25.94 ± 8.74] × 10-3 , SS magnitudes of the VCO were [28.67 ± 12.94] × 10-3 , P = 0.440; second specimen at 4 kHz, SS magnitudes of the CA were [23.79 ± 7.94] × 10-3 , SS magnitudes of the VCO were [24.78 ± 4.32] × 10-3 , P = 0.629; and third specimen at 5 kHz, SS magnitudes of the CA were [16.76 ± 6.20] × 10-3 , SS magnitudes of the VCO were [17.69 ± 6.44] × 10-3 , P = 0.643).The SS magnitudes of the VCO and PVCO of all the specimens extracted from the FFT at each frequency were statistically different (P < 0.001). CONCLUSIONS: Based on the FFT extraction, the SS magnitudes of the motor bur milling state between the CA and VCO, the VCO and PVCO were significantly different, confirming that the SS is a potential sensitive feedback parameter for identifying the motor bur milling state. This study could improve the safety of cervical spine posterior decompression surgery, especially of robot-assisted surgeries.

Glycine confers neuroprotection through microRNA-301a/PTEN signaling.

BACKGROUND: Glycine is known to protect against neuronal death. However, the underlying mechanism remains to be elucidated. The microRNA-301a is involved in both biological and pathological processes. But it is not known whether microRNA-301a has a neuroprotective property. In this study, we aimed to determine whether glycine-induced neuroprotection requires microRNA-301a-dependent signaling. RESULTS: We provided the first evidence that glycine increased the expression of microRNA-301a in cultured rat cortical neurons and protected against cortical neuronal death through up-regulation of microRNA-301a after oxygen-glucose deprivation. MicroRNA-301a directly bound the predicted 3'UTR target sites of PTEN and reduced PTEN expression in cortical neurons. We revealed that PTEN down-regulation by microRNA-301a mediated glycine-induced neuroprotective effect following oxygen-glucose deprivation. CONCLUSIONS: Our results suggest that 1) microRNA-301a is neuroprotective in oxygen-glucose deprivation-induced neuronal injury; 2) glycine is an upstream regulator of microRNA-301a; 3) glycine confers neuroprotection through microRNA-301a/PTEN signal pathway.

Experimental and Theoretical Investigations of the Bromination of Phenols with ß and γ Aliphatic Substituents, including Rings.

Bromination reactions of substituted and ring fused phenols were studied by both experiment (t-BuNH-Br) and computation (density functional theory). The outcomes support each other, indicating a clear and predictable regioselective preference among 3,4-bis-alkylated and 3,4-ring-fused phenols.

Surface modification of magnetite nanoparticles using gluconic acid and their application in immobilized lipase.

Superparamagnetic magnetite nanoparticles (SMN) were surface-modified with gluconic acid (GLA) to improve their hydrophilicity and bio-affinity. Gluconic acid was successfully coated on the surface of magnetite nanoparticles and characterized using Fourier transform infrared spectroscopy (FT-IR). With water-soluble carbodiimide (EDC) as the coupling reagent, lipase was successfully immobilized onto the hydroxyl-functionalized magnetic nanoparticles. The immobilized lipase had better resistance to temperature and pH inactivation in comparison to the free form and hence widened the reaction pH and temperature range. Thermostability and storage stability of the enzyme improved upon covalent immobilization. Immobilized lipase showed higher activity after recycling when compared to the free one and could be recovered by magnetic separation.

Dimethyl 3,3'-diphenyl-2,2'-[(S)-thio-phene-2,5-diylbis(carbonyl-aza-nedi-yl)]dipropano-ate tetra-hydro-furan monosolvate.

The title compound, C(26)H(26)N(2)O(6)S·C(4)H(8)O, a solvated bis-amide derivative, is also a chiral amino acid ester with l-phenyl-alanine methyl ester groups as amine substituents. The thio-phene-2,5-dicarboxamide core approximates C(2) point symmetry. The tetra-hydro-furan solvent mol-ecule is linked to the main mol-ecule through an inter-molecular N-H⋯O hydrogen bond. The central ring makes dihedral angles of 90.0 (2) and 76.5 (2)° with the pendant rings.

Bis(tetra-butyl-ammonium) bis-(3,4,5-trioxocyclo-pent-1-ene-1,2-dithiol-ato-κS,S')cadmate(II) 0.25-hydrate.

The title compound, (C(16)H(36)N)(2)[Cd(C(5)O(3)S(2))(2)]·0.25H(2)O, contains two disordered tetra-butyl-ammonium cations, a complex [Cd(C(5)O(3)S(2))(2)](2-) anion and a 0.25-hydrate water. The anion is composed of a bidentate coordinated 3,4,5-trioxocyclo-pent-1-ene-1,2-dithiol-ate (dtcroc) group forming a distorted tetra-hedral configuration around the Cd(II) ion. The dihedral angle between the least-squares planes of the ten-atom sulfur-substituted croconate groups in the anion is 84.10 (8)°. The crystal packing is stabilized by weak C-H⋯O and C-H⋯S cation-anion hydrogen-bond inter-actions. In each of the two cations one butyl group is disordered over two positions in the ratios 0.589 (11):0.411 (11) and 0.796 (12):0.204 (12).

Dimethyl 3,3'-diphenyl-2,2'-[(S)-thio-phene-2,5-diylbis(carbonyl-aza-nedi-yl)]dipropano-ate.

The asymmetric unit of the title compound, C(26)H(26)N(2)O(6)S, contains two independent mol-ecules; each has twofold symmetry with the S atom and the mid-point of the C-C bond of the thio-phene ring located on a twofold rotation axis. In the two mol-ecules, the terminal benzene rings are oriented at dihedral angles of 65.8 (3) and 63.5 (3)° with respect to the central thio-phene rings. The meth-oxy-carbonyl group of one mol-ecule is disordered over two positions with site-occupancy factors of 0.277 (12) and 0.723 (12). Inter-molecular N-H⋯O hydrogen bonding is present in the crystal structure.

5-(Methoxy-carbon-yl)thio-phene-2-carboxylic acid.

In the title compound, C(7)H(6)O(4)S, a monoester derivative of 2,5-thio-phene-dicarboxylic acid, the carboxylic acid and the carboxylic acid ester groups are approximately coplanar with thio-phene ring, making a dihedral angle of 3.1 (4) and 3.6 (4)°, respectively. In the crystal structure, mol-ecules are connected by classical inter-molecular O-H⋯O hydrogen bonds, forming centrosymmetric dimers.

1-Bromo-2,7-di-tert-butyl-pyrene.

In the title mol-ecule, C(24)H(25)Br, one of two tert-butyl groups is rotationally disordered between two orientations in a 0.59 (3):0.41 (3) ratio. The crystal packing exhibits no π-π inter-actions; however, relatively short inter-molecular Br⋯Br contacts of 3.654 (1) Šare observed.

(-)-Dimethyl 3,3'-diphenyl-2,2'-[pyridine-2,6-diylbis(carbonyl-imino)]dipropanoate.

The title compound, C(27)H(27)N(3)O(6), a bis-amide derivative, is also a chiral amino acid ester with l-phenyl-alanine methyl ester groups as amine substituents. The pyridine ring is oriented at dihedral angles of 89.69 (3) and 62.95 (3)° with respect to the phenyl rings, while the dihedral angle between the phenyl rings is 60.76 (3)°. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains. One of the carbonyl O atoms and one of the meth-oxy CH(3) groups are disordered over two positions. The O atom was refined with occupancies of 0.69 (13) and 0.31 (13), while C and H atoms were refined with occupancies of 0.69 (8) and 0.31 (8).

[Survey on knowledge, attitude and practices in asthmatic children's parents in Beijing].

OBJECTIVES: To study the knowledge, attitude and practice (KAP) concerning asthma in parents of children with asthma and the related factors. METHOD: Questionnaire survey was conducted by using the multi-center research methods in twenty hospitals with asthmatic clinic or pediatric clinic in Beijing from August to October in 2008. The investigation focused on Beijing permanent residents with children who have been diagnosed as asthma for more than 6 months. RESULT: Totally 390 parents of asthmatic children were investigated among whom 351 provided valid questionnaires, the response rate reached 90.0%; 75.2% of the parents knew that the nature of asthma is a chronic allergic airway inflammatory disease; 54.4% of parents think that even if the child is in a state of asthma control he/she can participate in only mild exercise; 88.4% of parents consider that the long-term use of inhaled corticosteroid would have a mild effect on growth and development of children. Of the asthmatic children, 32.5% adhered to use inhaled corticosteroid prescription; 47.2% adhered to use leukotriene receptor modulator; 45.3% of parents of children with acute asthma attack will add antibiotics; 18.1% of parents would choose short-acting beta2-agonist. The multi-factors Logistic regression suggested that the parents' educational background and the frequency of referral in children with asthma under control may have an influences on the parents' KAP (P < 0.05, OR > 1). CONCLUSION: The general understanding of asthma in asthmatic children's parents in Beijing area is good, the higher the parents' educational background and revisit frequency of asthmatic children whose disease is under control, the better the Parents' KAP.

[The clinical features and prognosis of Aeromonas septicaemia in hepatic cirrhosis: a report of 50 cases].

OBJECTIVE: Aeromonas septicaemia complicating cirrhosis is not a common infectious disease. To enhance the knowledge in this aspect, we analysed the clinical features, pathogenetic factors, resistance, treatment and prognosis of Aeromonas septicaemia in 50 cases of hepatic cirrhosis. METHODS: We cultured the bacteria from infected patients with BacT/Alert120 automation instrument made in AKsu and identified the bacteria with the Vitek-AMS60 made in Biomerieux company. We then tested the susceptibility of Aeromonas to 13 antimicrobial agents. RESULTS: A total of 50 cases of Aeromonas septicaemia occurred in severe hepatic cirrhosis. The majority of them had severe complications. Aeromonas hydrophila was the most common species isolated (52.0%). Nosocomial infection was the predominant way of infection. The major clinical manifestations of Aeromonas septicaemia were fever (100%), chill (64.0%), abdominal pain (60.0%), diarrhoea (32.0%) and shock (24.0%). The susceptive rate of Aeromonas to third generation cephalosporin, quinolones and aminoglycoside antibiotics was more than 80%. The cure rate and mortality attributed to Aeromonas septicaemia after treating with third generation cephalosporin, levofloxacin and their combination were 64.3%, 75.0%, 57.1% and 28.6%, 12.5%, 35.7% respectively. CONCLUSION: Aeromonas septicaemia tends to befall patients with severe hepatic cirrhosis and causes a rapidly fatal outcome. Aeromonas should be considered an important pathogen for septicemia in patients with liver cirrhosis. It is suggested that we should emphasize the clinical features and laboratory diagnosis so as to have proper antimicrobial treatment.