Programmable T-Junction Structure-Assisted CRISPR/Cas12a Electrochemiluminescence Biosensor for Detection of Sa-16S rDNA.

Herein, a strand displacement amplification (SDA)-assisted CRISPR/Cas12a (LbCpf1) electrochemiluminescence (ECL) biosensor was fabricated for ultrasensitive identification of Staphylococcus aureus (Sa)-16S rDNA. A porphyrinic Zr metal-organic framework (MOF) (PCN-224) nanomaterial was prepared as the coreactant accelerator, which promoted the conversion of S2O82- and SO4*-, thus enhancing the reaction with CdS quantum dots (QDs) and amplifying the ECL emission signal. Meanwhile, with the presence of Sa-16S rDNA, the auxiliary probes and primers stimulated the SDA reaction under the action of Klenow fragment (3'-5' exo-) and Nt. BbvCI specifically recognized Sa-16S rDNA to form a defective T-junction structure and generated second primers to initiate the cycles. Such a structure transformed the input signal (Sa-16S rDNA) into substantial single-stranded DNA products (SP) through SDA. SP acted as activators and activated arbitrary side chain cleavage of CRISPR/Cas12a (trans-cleavage) and further realized effective annihilation of ECL signals. This ECL platform demonstrated desirable assay performance for Sa-16S rDNA with a wide response range of 1 fM to 10 nM, and the limit of detection was 0.437 fM (S/N = 3), showing good sensitivity and specificity. Therefore, the method not only expanded the applications of CRISPR/Cas12a but also opened up a novel strategy for clinical diagnosis.

Treatment of acetabular fracture involving anterior and posterior columns using a single pararectus approach: surgical experience and preliminary results.

PURPOSE: This study aims to evaluate the efficacy of single pararectus approach in patients confirmed with acetabular fracture involving anterior and posterior columns. METHODS: A total of 58 patients confirmed with acetabular fracture involving anterior and posterior columns and treated at our hospital between January 2015 and January 2020 were retrospectively analyzed. A single pararectus approach was applied for all patients. Routine X-rays were performed at follow-up of one, three, six, 12, and 18 months, and three-dimensional CT scans were added at six and 18 months. Fracture reduction quality was assessed using the Matta score system, and functional assessment used the Modified Merle D'Aubigné and Postel score system. Post-operative complications, including fat liquefaction and deep vein thrombosis, were recorded and analyzed. RESULTS: The median operation time was 186 min while the intra-operative blood loss was 421 mL. The rate of good-to-excellent reduction was 94.8%, and the rate of good-to-excellent hip function score reached 93.1%. Seven patients presented with post-operative complications, including three intra-operative small vascular injuries, two peritoneal small perforations, one fat liquefaction, and one deep vein thrombosis. CONCLUSION: Using a single pararectus approach is convenient and effective for treating acetabular fracture involving anterior and posterior columns, especially those involving the quadrilateral area. TRIAL REGISTRATION: ChiCTR, ChiCTR2100054604. Registered 21 December 2022. Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=144783 .

[TiRobot-assisted surgery by O-arm navigation system for percutaneous minimally invasive treatment of posterior pelvic ring injury].

Objective: To evaluate the effectiveness of TiRobot-assisted surgery by O-arm navigation system for percutaneous minimally invasive treatment of posterior pelvic ring injury. Methods: The clinical data of 76 patients with posterior pelvic ring injury between January 2016 and June 2021 were retrospectively analyzed. Among them, 45 cases were treated with minimally invasive percutaneous sacroiliac screw fixation assisted by TiRobot and O-arm navigation system (study group), 31 cases were treated with minimally invasive percutaneous sacroiliac screw fixation under the guidance of C-arm X-ray machine (control group). There was no significant difference in gender, age, cause of injury, Tile classification, time from injury to operation between the two groups ( P>0.05). The operation time, intraoperative blood loss, the times of nail track adjustment, and intraoperative fluoroscopy times were recorded. The quality of fracture reduction was evaluated by Matta score. At last follow-up, Majeed score was used to evaluate the recovery of pelvic function. Results: A total of 72 screws were implanted in the study group, with a median of 1 (1, 2) screws per patient. In the control group, 47 screws were implanted, with a median of 1 (1, 2) screws per patient. There was no significant difference in the number of screws between the two groups ( Z=-0.392, P=0.695). The operation time, intraoperative blood loss, times of nail track adjustment, and intraoperative fluoroscopy times in the study group were significantly less than those in the control group ( P<0.05). All patients were followed up 6-24 months (mean, 14 months). No serious complications was found after operation and during follow-up. Matta score was used to evaluate the quality of fracture reduction at 1 week after operation, and there was no significant difference between the two groups ( Z=-1.135, P=0.256). At last follow-up, there was no significant difference of Majeed score between the two groups ( Z=-1.279, P=0.201). Conclusion: TiRobot-assisted surgery by O-arm navigation system is a reliable surgical method for the treatment of posterior pelvic ring injury, which can reduce the operation time and fluoroscopy times when compared with the traditional operation under the guidance of C-arm X-ray machine. The safety, accuracy, and efficiency of the operation were improved.

Configuration of short- and long-threaded cannulated screws in proximal femoral plating decreases varus collapse of femoral neck fractures: A retrospective cohort study.

OBJECTIVES: Proximal femoral plating serves as a good alternative for the fixation of femoral neck fractures, but fixation loss still occurs. This study aimed to evaluate the effect of a hybrid configuration of short- and long-threaded cannulated screws in proximal femoral plating in terms of decreasing varus collapse of femoral neck fractures. MATERIALS AND METHODS: We retrospectively analyzed 86 patients with femoral neck fractures who were fixed by proximal femoral plating from January 2015 to June 2019. These patients were divided into two groups according to screw configuration: short- and long-threaded cannulated screws (SLTS, n = 38) and short-threaded cannulated screws (STS, n = 48). Radiological and clinical outcomes including screw withdraw, nonunion, avascular necrosis, caput-collum-diaphysis (CCD) angle, amount of femoral neck shortening (FNS), and Harris Hip Score (HHS) were compared between the groups. RESULTS: Preoperative characteristics including age, gender, Garden type, duration of surgery, and reduction quality were not significantly different between the two groups (p > 0.05). Less decreased CCD angle was observed in the SLTS group (-0.4° (-1.4 - 1.8)) compared with that in the STS group (7.9° (6.3 - 11.0)) (p < 0.001). The SLTS group also presented with fewer amount of FNS (3.2 (2.7 - 3.8) mm vs. 5.1 (4.2 - 5.9) mm, p < 0.001). Bone union was achieved in all patients and no avascular necrosis was observed during the follow-up. The HHS was higher in the SLTS group (86.4 ± 5.1) than that in the STS group (81.5 ± 4.5) (p < 0.001). CONCLUSION: The hybrid configuration of short- and long-threaded screws in proximal femoral plating offers better resistance against varus collapse and yields better functional outcomes in femoral neck fractures.

Dynamic limited axial compression yields favorable functional outcomes in the fixation of Pauwels type-3 femoral neck fractures: A retrospective cohort study.

PURPOSE: Pauwels type-3 femoral neck fractures are challenging injuries to manage with high rates of complications after internal fixation and no consensus has been reached regarding the optimal fixation construct. The current study aims to evaluate the effect of dynamic limited axial compression in parallel screws combined with medial buttress plate (SMBP) or lateral compression plate (LCP) fixation of Pauwels type-3 femoral neck fractures. METHODS: We performed a retrospective analysis of 51 cases of Pauwels type-3 femoral neck fractures who were fixed by SMBP or LCP. Specifically, the screw fixing the femoral head in the buttress plate was omitted. Postoperative complications and functional outcomes were mainly studied. RESULTS: With a mean follow-up of 19.9 months, the rate of neck shortening was higher in the LCP group than that in SMBP group (32.1% vs. 8.7%, p = 0.04). Neither nonunion nor avascular necrosis was observed in both groups. Good-to-excellent Harris hip score accounts for 95.2% in SMBP group and 89.3% in LCP group (p = 0.40). Moreover, older age, fracture comminution and compression plate fixation predispose to neck shortening. CONCLUSION: Dynamic limited axial compression by SMBP or LCP fixation was effective to improve the functional outcome of patients with Pauwels type-3 femoral neck fractures.

Fabrication of multi-functional porous microspheres in a modular fashion for the detection, adsorption, and removal of pollutants in wastewater.

Water pollution control has become significant challenges in recent years because of their extensive species diversity. It is critical to developing general-purpose materials for environmental rehabilitation. In this paper, a novel module-assembly method is developed to prepare multi-functional materials for treating pollutants in water. Building blocks are porous nanoparticles with a different function. Microspheres (MS) with a diameter of 90 µm are prepared and have a coefficient of variation of 6.8%. The modular fashion of self-assembly process in a microfluidic chip is the crucial factor in fabricating the multifunction material. The assembled microspheres with different building modules still have a specific surface area larger than 400 m2 g-1, and exhibit excellent performance in adsorbing various pollutants in water, such as heavy metal ions and organic dyes. The adsorption capacities of them to Hg2+ and orange II reach 150 mg g-1 and 333 mg g-1, respectively. The integrated fluorescence probes in microspheres can detect low concentration (9.8 ppb) of Hg2+. Microspheres integrated with Fe3O4 nanoparticles have a magnetic susceptibility of 6.01 emu g-1 and can be easily removed from wastewater by applying an external magnetic. Due to the stability of inorganic building blocks, each function in the assembled system is well performed, and multi-functional "All-in-One" materials can be easily fabricated.

Shaping 3D Path of Electromagnetic Waves Using Gradient-Refractive-Index Metamaterials.

An all-dielectric semispherical lens with functions in shaping 3D wave-propagation paths is proposed and experimentally verified. When radiation sources are placed in the central region, the lens behaves as a magnifying device to resolve the sources in subwavelength scale; while when the electromagnetic waves impinge on the semispherical lens from outside, they will be guided spirally inward.

An Optically Controllable Transformation-dc Illusion Device.

The concept of multifunctional transformation-dc devices is proposed and verified experimentally. The functions of dc metamaterials can be remotely altered by illuminating with visible light. If the light-induced dc illusion effect is activated, the electrostatic behavior of the original object is perceived as multiple equivalent objects with different pre-designed geometries. The experimental verification of the functional device makes it possible to control sophisticated transformation-dc devices with external light illumination.