Indirect Reduction Research Articles

Acclimation of Photosynthesis to CO2 Increases Ecosystem Carbon Storage due to Leaf Nitrogen Savings.

Photosynthesis is the largest flux of carbon between the atmosphere and Earth's surface and is driven by enzymes that require nitrogen, namely, ribulose-1,5-bisphosphate (RuBisCO). Thus, photosynthesis is a key link between the terrestrial carbon and nitrogen cycle, and the representation of this link is critical for coupled carbon-nitrogen land surface models. Models and observations suggest that soil nitrogen availability can limit plant productivity increases under elevated CO2. Plants acclimate to elevated CO2 by downregulating RuBisCO and thus nitrogen in leaves, but this acclimation response is not currently included in land surface models. Acclimation of photosynthesis to CO2 can be simulated by the photosynthetic optimality theory in a way that matches observations. Here, we incorporated this theory into the land surface component of the Energy Exascale Earth System Model (ELM). We simulated land surface carbon and nitrogen processes under future elevated CO2 conditions to 2100 using the RCP8.5 high emission scenario. Our simulations showed that when photosynthetic acclimation is considered, photosynthesis increases under future conditions, but maximum RuBisCO carboxylation and thus photosynthetic nitrogen demand decline. We analyzed two simulations that differed as to whether the saved nitrogen could be used in other parts of the plant. The allocation of saved leaf nitrogen to other parts of the plant led to (1) a direct alleviation of plant nitrogen limitation through reduced leaf nitrogen requirements and (2) an indirect reduction in plant nitrogen limitation through an enhancement of root growth that led to increased plant nitrogen uptake. As a result, reallocation of saved leaf nitrogen increased ecosystem carbon stocks by 50.3% in 2100 as compared to a simulation without reallocation of saved leaf nitrogen. These results suggest that land surface models may overestimate future ecosystem nitrogen limitation if they do not incorporate leaf nitrogen savings resulting from photosynthetic acclimation to elevated CO2.

Physical climate change risk and ESG green premium

ABSTRACT We build an asset pricing model that incorporates climate change risk and firms’ ESG engagement to analyse their interactive effects on equity returns. Our model shows that a firm’s ESG engagement has three channels for influencing stock returns: its direct impact on resisting climate change risk, indirect reduction in systematic risk and attraction of green preference, and the empirical evidence shows that both risk–return relation and ESG engagement are priced. We also point out an inevitably negative and convex relation between the market Sharp Ratio and stocks market beta in an economy with climate change risk.

Isolated Ni Atoms for Enhanced Photocatalytic H2O2 Performance with 1.05% Solar-to-Chemical Conversion Efficiency in Pure Water.

Photocatalytic hydrogen peroxide (H2O2) production encounters a major impediment in its low solar-to-chemical conversion (SCC) efficiency due to undesired H2O2 product decomposition. Herein, an isolated nickel (Ni) atom modification strategy is developed to adjust the thermodynamic process of H2O2 production to address the challenge. Sacrificial experiments and in situ characterization reveal that H2O2 generation occurs via a highly selective indirect two-electron oxygen reduction reaction. The optimized photocatalyst exhibits a remarkable H2O2 production rate of 338.9 μmol gcat-1 h-1 in pure water, representing a 48-fold enhancement. Notably, it attains an impressive SCC efficiency of 1.05%, surpassing that of current state-of-the-art catalysts. Theoretical insights reveal the downshifted d-band center facilitates moderate O2 adsorption and barrier-free *OOH conversion, favoring H2O2 release and preventing *H2O2 decomposition. This work showcases efficient H2O2 photosynthesis via d-band manipulation, presenting a fresh perspective for advancing high-efficiency SCC systems.

Mathematical Modeling and Indirect Carbon Emission Reduction Analysis of Urban Wastewater Treatment Systems Under Different Temperature Conditions

In the context of achieving the two-carbon target, this study utilized a wastewater treatment plant in Shenyang City as a case study to accurately calculate indirect emissions related to energy and chemical consumption within the energy-intensive wastewater treatment industry. Sumo software was employed for precise mathematical modeling. Considering the operational characteristics of wastewater treatment plants in cold regions, this study innovatively divided the annual operation cycle into two periods, namely normal temperature and low temperature, and determined the optimal operational parameters under a low-carbon mode. The results indicate that precise regulation of dissolved oxygen concentration to 0.5–1.5 mg/L (normal temperature period) and 1–2 mg/L (low temperature period) can significantly reduce carbon emissions related to electricity consumption by 13,781.9 t CO2-eq. From the perspective of chemical consumption, adjusting the dosage of polyaluminum chloride (PAC) to 75% and sodium acetate to 70% during the normal temperature period can lead to a reduction in indirect carbon emissions of 1614.4 t CO2-eq compared to the same period last year. During the low-temperature period, by reducing the dosage of polyaluminum chloride to 80% and sodium acetate to 75%, the indirect carbon emissions can be reduced by 1557.3 t CO2-eq compared to the corresponding period last year. After optimization, USD 1.49 million can be saved. This study simulated the operation conditions of cold-region urban wastewater treatment plants at different times to effectively control carbon emissions resulting from energy and chemical consumption in wastewater treatment. This result can provide innovative ideas for energy saving and carbon reduction in cold-region wastewater treatment plants.

Microbial fuel cells: A potent and sustainable solution for heavy metal removal

The global water pollution problem is becoming increasingly crucial. One of the major contributors to water pollution is the presence of heavy metals. Heavy metals pose significant threat to both humans and all ecosystems. Various factors influence the removal of heavy metals from wastewater, including pH, temperature, natural organic matter (NOM), and ionic strength, which vary based on the chemical properties of the pollutants. More effective and modern approaches receive attention and extensively researched to substitute traditional methods such as adsorption, membrane filtration, and chemical-based separation. Among these methods, Microbial fuel cells (MFCs) are particularly intriguing. This review article focuses on MFCs and their potential applications in various fields, including clean water production. MFCs represent an innovative technology that not only generates electricity, but also demonstrates significant potential for heavy metal removal from wastewater. Cathodic chamber of MFCs effectively reduces heavy metals, while organic substrates act as carbon and electron donors in the anodic chamber. Through various mechanisms, including direct and indirect metal reduction, biofilm formation (metal sequestering), electron shuttling, and synergistic interactions among microbial communities, microorganisms exhibit remarkable efficiency in removing metals. Studies showed that dual- and single-chamber MFCs could efficiently remove a range of heavy metals, including chromium, cobalt, copper, vanadium, mercury, gold, selenium, lead, magnesium, manganese, zinc, and sodium, while simultaneously generating electricity, achieving high removal efficiencies ranging from 25% to 99.95%. This range of efficiency varies depending on the specific contaminant being targeted, the concentration of the contaminant, as well as the operating conditions such as pH and temperature. Moreover, MFCs demonstrated a wide range of power outputs, typically ranging from 0.15 W/m² to 6.58 W/m², depending on the specific configuration and conditions. These findings underscore the potential of MFCs as a sustainable and efficient approach for both wastewater treatment and energy generation.

Bisulfite enhances p-nitrophenol degradation by zero-valent iron under oxic conditions: Combination of indirect reduction by superoxide radical and direct reduction

Advanced oxidation processes based on the combination of zero-valent iron (ZVI) and S(IV) have been extensively investigated for oxidative degradation of organic pollutants, but little attention has been paid to their reducing capacities in the presence of oxygen. This work found bisulfite (BS) could greatly enhance the degradation of p-nitrophenol (PNP) by ZVI under oxic conditions and PNP was only reduced to p-aminophenol without further degradation. A combination of indirect reduction by superoxide radical (O2•–) and direct reduction by ZVI was verified as the mechanism of PNP degradation. Highly oxidizing species, such as hydroxyl radical (HO•) and sulfate radical (SO4•−), were also produced in the ZVI/BS system under oxic conditions but did not contribute to pollutant degradation perhaps due to the rapid consumption by reducing substances like BS ions and the released Fe2+. BS concentration, ZVI dosage, initial solution pH and coexisting anions (CO32–, PO43– and Cl–) affected the degradation of PNP. ZVI lost the reactivity after used for three times because of the production of goethite and lepidocrocite covered on its surface. This study will provide a new insight into degradation of organic pollutants in ZVI/BS system under oxic conditions.

Intranasal Outer Cortex Splinting With a Kirschner Wire to Immobilize Reduced Buckle-out Segments in Nasal Fractures

High-velocity lateral impacts to the nose sometimes cause nasal buckle-out fractures with a trapdoor buckle-out segment displaced outwards. Prolonged immobilization of a reduced buckle-out segment at risk for outward redisplacement remains challenging. Here we introduce a novel method of intranasal outer cortex splinting with a Kirshner (K)-wire to reinforce the reduced state and prevent outward re-displacement of the buckle-out segment. Eighteen patients with nasal buckle-out fractures underwent outer cortex K-wire splinting to securely immobilize a reduced but unstable buckle-out segment after indirect open reduction through intercartilaginous incisions and inner cortex K-wire splinting. A thin K-wire (diameter 0.8 mm) was inserted at the vestibule, passed above the upper lateral cartilage and the outer cortex of the reduced buckle-out segment, and extended to the cephalic non-fractured bone. The wire served as a crossbeam, effectively supporting the reduced buckle-out segment. All K-wires for inner and outer cortex splinting were removed 10 to 14 days postoperatively. Immediate postoperative computed tomography scans showed successful immobilization of buckle-out segments in 17 patients (94.5%). Postoperative 6-month scans of 7 patients showed excellent maintenance and bony alignment of buckle-out segments in all cases. Sixteen patients (88.9%) were satisfied with the overall external nasal contour at the last follow-up. There were no complications directly related to outer cortex K-wire splinting. One patient complained of a focal lateral protrusion resulting from the under-correction of a buckle-out segment. This technique may be a valuable option for immobilizing and maintaining reduced nasal buckle-out segments until a stable bony union is established.

Synergistic effect of lightning rod and piezo-photocatalysis in sea urchin-shape Zn-MOF-74@g-C3N4 step-scheme heterojunction for H2O2 production under visible light irradiation

Piezo-photocatalytic H2O2 production was an emerging environmental technology that could convert solar energy into green chemicals, garnering significant attention. This study combined lightning rod effect and piezo-photocatalysis to achieve H2O2 production through an indirect two-electron oxygen reduction reaction pathway. A composite catalyst, sea urchin-shaped Zn-MOF-74@g-C3N4, had a surface of spherical Zn-MOF-74 made up of graphite phase carbon nitride nanoneedles with high curvature tips. These tips could induce a “lightning rod effect” property, accelerating charge transfer and separation by guiding electron migration along the sharp tip direction. The piezo-photocatalytic process, along with the construction of step-scheme heterojunction, generated a dual electric field, significantly enhancing the separation and migration rate of photogenerated carriers. As a result, the prepared Zn-MOF-74@g-C3N4 demonstrated a higher H2O2 production rate under the synergistic effect of lightning rod and piezo-photocatalysis. Free radical trapping experiments were conducted on various active species to uncover the mechanism behind the piezo-photocatalytic dual electric field coupling to produce H2O2.

Pilon fracture with central articular surface collapse treated by posterior tibial fenestration indirect reduction and compression technique: Two cases report.

Central collapsed fracture blocks traditionally require either an anteromedial or anterolateral approach for reduction. However, existing techniques face challenges such as soft tissue damage and compromised tibial strength, especially in pilon fractures with central articular surface collapse and an intact anterior cortex, as classified under 43B2.3 in the 2018 Orthopaedic Trauma Association/Association for the Study of Internal Fixation Fracture and Dislocation Classification Compendium. We address the management of pilon fractures with central articular surface collapse, focusing on 2 cases where conventional reduction techniques posed a risk to soft tissues and tibial integrity. The patients presented with pilon fractures characterized by a central articular surface collapse and an intact anterior cortex, aligning with the 43B2.3 classification. A novel approach was employed, utilizing posterior tibial fenestration and indirect reduction with compression techniques. This method leveraged the talus as a template for precise articular surface realignment. Both cases demonstrated excellent reduction of the distal tibial articular surface and achieved favorable functional recovery of the ankle, evidenced by high American Orthopedic Foot and Ankle Society Ankle Hindfoot Scale scores during the 3-year follow-up. The posterior tibial fenestration technique offers significant advantages for distal tibial pilon fracture reduction. It allows for precise articular realignment, facilitates bone grafting, and minimizes soft tissue and cortical bone disruption. This method is particularly effective for pilon fractures with an intact anterolateral cortex and central articular collapse, providing a valuable surgical alternative.

Nitrogen-Site Engineering in Covalent Organic Frameworks for H2O2 Photogeneration via Dual Channels of Indirect Two-Electron O2 Reduction.

Photocatalytic H2O2 production is a green and sustainable route, but far from meeting the increasing demands of industrialization due to the rapid recombination of the photogenerated charge carriers and the sluggish reaction kinetics. Effective strategies for precisely regulating the photogenerated carrier behavior and catalytic activity to construct high-performance photocatalysts are urgently needed. Herein, a nitrogen-site engineering strategy, implying elaborately tuning the species and densities of nitrogen atoms, is applied for H2O2 photogeneration performance regulation. Different nitrogen heterocycles, such as pyridine, pyrimidine, and triazine units, are polymerized with trithiophene units, and five covalent organic frameworks (COFs) with distinct nitrogen species and densities on the skeletons are obtained. Fascinatingly, they photocatalyzed H2O2 production via dominated two-electron O2 reduction processes, including O2-O2 •‒-H2O2 and O2-O2 •‒-O2 1-H2O2 dual pathways. Just in the air and pure water, the multicomponent TTA-TF-COF with the maximum nitrogen densities triazine nitrogen densities exhibited the highest H2O2 production rate of 3343µmol g-1 h-1, higher than most of other reported COFs. The theoretical calculation revealed the higher activity is due to the easy formation of O2 •‒ and O2 1 in different catalytic process. This study gives a new insight into designing photocatalysis at atomic level.

Effectiveness comparison of open reduction and hook plate fixation versus closed indirect reduction and dorsal extension blocking Kirschner wire fixation for bony mallet finger

To compare the effectiveness of open reduction and hook plate fixation versus closed indirect reduction and dorsal extension blocking Kirschner wire fixation for bony mallet fingers. The clinical data of 68 patients with bony mallet finger who admitted between May 2019 and June 2022 were retrospectively analyzed. Among them, 33 cases were in the open group (treated with open reduction and hook plate fixation) and 35 cases were in the closed group (treated with closed indirect reduction and dorsal extension blocking Kirschner wire fixation). There was no significant difference between the two groups in terms of gender, age, the affected side, the affected finger, cause of injury, time from injury to operation, and Wehbé-Schneider classification ( P>0.05). The operation time, intraoperative fluoroscopy frequency, fracture healing time, time of returning to work, and postoperative complications were recorded and compared between the two groups. At 12 months after operation, visual analogue scale (VAS) score was used to assess the pain of the injured finger, active flexion range of motion and extension deficit of the distal interphalangeal joint (DIP) were measured by goniometer, and the effectiveness was assessed by Crawford criteria. All patients in the two groups were followed up 12-26 months, with an average of 15 months. There was no significant difference in the follow-up time between the closed group and the open group ( P>0.05). The operation time in the closed group was shorter than that in the open group, and the intraoperative fluoroscopy times, the fracture healing time, and the time of returning to work in the closed group were more than those in the open group, and the differences were significant ( P<0.05). In the closed group, there were 5 cases of pinning tract infection and 3 cases of small area pressure ulcer skin necrosis on the dorsal side of the finger, which were cured after intensive nursing and dressing change. Local nail depression deformity occurred in 7 cases in the open group, and the deformity disappeared after removal of plate. The incisions of the other patients healed uneventfully without complications such as infection, skin necrosis, exposure of the internal fixation, or nail deformity. There was no significant difference in the incidence of skin necrosis between the two groups ( P>0.05), but the differences in the incidence of infection and nail deformity between the two groups were significant ( P<0.05). There was no significant difference in VAS score, DIP active flexion range of motion, DIP extension deficiency, or Crawford criteria evaluation between the two groups at 12 months after operation ( P>0.05). At last follow-up, there was no DIP osteoarthritis and joint degeneration in both groups. Open reduction and hook plate fixation versus closed indirect reduction and dorsal extension blocking Kirschner wire fixation have their own advantages and disadvantages, but both of them have good results in the treatment of bony mallet fingers. Open reduction and hook plate fixation is recommended for young patients with bony mallet fingers who are eager to return to work.

A local acidic environment at the copper/molten salt interface enabling the efficient CO2 to CO conversion

The electrochemical reactions highly rely on the chemical environments, however, this phenomenon remains poorly understood in nonaqueous electrolyte. Herein, we study the effect of the electrode chemical environments on the electrochemical reduction of CO2 in molten carbonate. Using a Cu foam electrode, an acidic (CO2-rich) environment is created to achieve the efficient direct reduction of CO2 rather than the indirect reduction of CO32–. The acidic environment promotes a selective CO production thermodynamically, achieving a high CO current efficiency of 99 % at a current density of 779–1039 mA cm−2 at 700 °C. The Cu foam electrode works stably over 100 h at 260 mA cm−2 with an overpotential of 304 mV. This work reveals the role of the local chemical environment at the electrode/molten salt interface in governing the product selectivity and energy consumption, which is helpful for designing efficient high-temperature CO2 electrolyzers.

The screening of iron oxides for long-term transformation into vivianite to recover phosphorus from sewage

The reducibility of iron oxides, depending on their properties, influences the kinetics of dissimilatory iron reduction (DIR) during vivianite recovery in sewage. This study elucidated the correlation between properties of iron oxides and kinetics of DIR during the long-term transformation into vivianite, mediated by Geobacter sulfurreducens PCA and sewage. The positive correlation between surface reactivity of iron oxides and reduction rate constant (k) influenced the terminal vivianite recovery efficiency. Akaganeite with the highest adhesion work and surface energy required the lowest reduction energy (Ea), obtained the highest k of 1.36 × 10–2 day-1 and vivianite recovery efficiency of 43 %. The vivianite yield with akaganeite as iron source was 76–164 % higher than goethite, hematite, feroxyhyte, and ferrihydrite in sewage. The distribution of P with akaganeite during DIR in sewage further suggested a more efficient pathway of direct vivianite formation via bio-reduced Fe(II) rather than indirect reduction of ferric phosphate precipitates. Thus, akaganeite was screened out as superior iron source among various iron oxides for vivianite recovery, which provided insights into the fate of iron sources and the cycle of P in sewage.

Ferric citrate enhanced bioreduction of Cr(VI) by Bacillus cereus RCr in aqueous solutions: reduction performance and mechanisms.

The bioreduction characteristics and mechanisms of Cr(VI) onto Bacillus cereus RCr enhanced by ferric citrate were investigated. The optimum conditions were initial pH 9, temperature 40°C, inoculation amount 4%, and glucose 3g/L, respectively. The addition of 1.5g/L ferric citrate increased the average reduction rate from 120.43 to 220.61mg/(L∙h) compared with the control (without ferric citrate). The binding capacity of Cr(III) on the cell surface increased to 21%, in which the precipitates were mainly CrO(OH), Cr2O3, and FeCr2O4. Cell membrane was the main site of reduction, related important functional groups: - COOH, C-H, - NH2, C = C, and P-O. Fe(III) increased the yield of NADH and cytochrome c by approximately 48.51% and 68.63%, which significantly facilitated the electron generation and electron transfer, thus increasing the amount of electrons in the bioreduction of heavy metals by an average of 110%. Among the electrons obtained by Cr(VI), the proportion of indirect reduction mediated by Fe(III)/Fe(II) shuttle was 62% on average, whereas direct reduction mediated by reductase was 38%. These results may provide insights into the bioreduction process by bacteria enhanced by Fe(III) for detoxification of heavy metals with multiple valences, as an important step towards improving microbial remediation.

Virtual surgical planning and use of a 3D-printed, patient-specific reduction system for minimally invasive plate osteosynthesis of diaphyseal tibial fractures in dogs: A historic case control study.

To compare the efficacy and clinical outcomes of computed tomography (CT)-based virtual surgical planning (VSP) and a three-dimensional (3D)-printed, patient-specific reduction system to conventional indirect reduction techniques for diaphyseal tibial fractures stabilized using minimally invasive plate osteosynthesis (MIPO) in dogs. A prospective clinical study with a historic control cohort. Dogs undergoing MIPO stabilization of diaphyseal tibial fractures using a custom 3D-printed reduction system (3D-MIPO; n = 15) or conventional indirect reduction techniques (c-MIPO; n = 14). Dogs were prospectively enrolled to the 3D-MIPO group and CT scans were used to design and fabricate a custom 3D-printed reduction system to facilitate MIPO. Medical records were searched to identify dogs for the c-MIPO group. Pre-, intra- and postoperative parameters were compared between groups. The duration from presentation until surgery was 23 h longer in the 3D-MIPO group (p = .002). Fewer intraoperative fluoroscopic images were acquired (p < .001) and mean surgical duration was 34 min shorter in the 3D-MIPO group (p = .014). Median postoperative tibial length, frontal alignment, and sagittal alignment were within 4 mm, 3° and 3°, respectively, of the contralateral tibia in both groups and did not differ between reduction groups (p > .1). Postoperative complications occurred in 27% and 14% of fractures in the 3D-MIPO and c-MIPO groups, respectively. Both reduction methods yielded comparable results. Although the preoperative planning and guide preparation was time consuming, surgery times were shorter and fluoroscopy use was lessin the 3D-MIPO group. VSP and the custom 3D-printed reduction system facilitated efficient MIPO.

New Perspective to Evaluate the Carbon Offsetting by Urban Blue-Green Infrastructure: Direct Carbon Sequestration and Indirect Carbon Reduction.

Urban blue-green infrastructure (BGI) offers a multitude of ecological advantages to residents, thereby playing a pivotal role in fortifying urban resilience and fostering the development of climate-resilient cities. Nonetheless, current research falls short of a comprehensive analysis of BGI's overall potential for carbon reduction and its indirect carbon reduction impact. To fill this research gap, we utilized the integrated valuation of ecosystem services and trade-offs model and remote sensing estimation algorithm to quantify the direct carbon sequestration and resultant indirect carbon reduction facilitated by the BGI within the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) (China). To identify the regions that made noteworthy contributions to carbon offsets and outliers, spatial autocorrelation analysis was also employed. The findings of this study reveal that in 2019, the BGI within the study area contributed an overall carbon offset of 1.5 × 108 t·C/yr, of which 3.5 × 107 and 11.0 × 107 t·C/yr were the result of direct carbon sequestration and indirect carbon reduction, respectively. The GBA's total CO2 emissions were 1.1 × 108 t in 2019. While the direct carbon sequestration offset 32.0% of carbon emissions, the indirect carbon reduction mitigated 49.9% of potential carbon emissions. These results highlight the critical importance of evaluating BGI's indirect contribution to carbon reduction. The findings of this study provide a valuable reference for shaping management policies that prioritize the protection and restoration of specific areas, thereby facilitating the harmonized development of carbon offset capabilities within urban agglomerations.

High-purity ethylene production via indirect carbon dioxide electrochemical reduction

High-purity ethylene production from CO2 electroreduction (CO2RR) is a coveted, yet arduous feat because the product stream comprises a blend of unreacted CO2, H2, and other off-target CO2 reduction products. Here we present an indirect reduction strategy for CO2-to-ethylene conversion, one that employs 2-bromoethanol (Br-EO) as a mediator. Br-EO is initially generated from CO2RR and subsequently undergoes reduction to ethylene without the need for energy-intensive separation steps. The optimized AC-Ag/C catalyst with Cl incorporation reduces the energy barrier of the debromination step during Br-EO reduction, and accelerates the mass-transfer process, delivering a 4-fold decrease of the relaxation time constant. Resultantly, AC-Ag/C achieved a FEethylene of over 95.0 ± 0.36% at a low potential of −0.08 V versus reversible hydrogen electrode (RHE) in an H-type cell with 0.5 M KCl electrolyte, alongside a near 100% selectivity within the range of −0.38 to −0.58 V versus RHE. Through this indirect strategy, the average ethylene purity within 6-hour electrolysis was 98.00 ± 1.45 wt%, at −0.48 V (vs RHE) from the neutralized electrolyte after CO2 reduction over the Cu/Cu2O catalyst in a flow-cell.

Open Reduction and Internal Fixation versus Minimally Invasive Plate Osteosynthesis in Management of Distal Tibia Extra-Articular Fracture (Mini Thesis)

Abstract Background Extra-articular distal tibia fracture is one of the difficult fractures to treat and the optimal treatment remains controversial, however plates seem to be the obvious choice for treating this type of fractures. The mechanism on how to achieve the balance between anatomic reduction and indirect reduction as well as direct and indirect healing remains unclear. Thus, the key point is whether to use ORIF or MIPO in treating fractures. Aim of the Work to provide a complete overview of the optimal plating technique for distal tibia fractures by evaluating and comparing the clinical and functional outcomes of minimally invasive plate osteosynthesis (MIPO) vs Open reduction and internal fixation (ORIF) for treating extra- articular distal tibial fractures. Outcomes of interest include operation time, time to union, non-union, mal-union, infection, secondary operations, and functional outcomes (AOFAS score). Patients and Methods From August 2020 to August 2021, a prospective randomized study was conducted at the department of orthopedic surgery of Ain-shams University Hospital including 36 patients to compare MIPO vs. ORIF in fixation of extra-articular distal tibial fractures. The patients were allotted to the MIPO or ORIF group with the flip of a coin. Results Regarding complications rate, no cases developed infection in MIPO technique. On the other hand, the ORIF technique had an infection incidence of 16.6% overall, with two cases (11.11 %) developing superficial infection and one case (5.56 %) developing deep infection. There was no significant difference in the incidence of mal-union between both techniques with no cases of non-union in both groups. The MIPO group had only one case of sagittal plane malunion (5.56%), compared with no cases in the ORIF group. There was no significant difference between both groups in secondary operations rate, with one case in each group. Conclusion Both MIPO and ORIF have similar therapeutic efficacy regarding the functional outcome and can be used safely in distal tibial extra-articular fractures. Although MIPO is advantageous over ORIF with earlier weight-bearing, earlier union, and clinical lower incidence of infection, it has delayed operation time.

Treatment of Acute Acromioclavicular Joint Dislocation Using Hook Plate: A Systematic Review and Meta-Analysis and Update of Current Literature

Abstract Background the hook plate metallic device showed early promise as an alternative implant to treat unstable acromioclavicular joint dislocation injuries. The hook plate can be used to provide an indirect reduction of a distal clavicle fracture. This indirect reduction technique is useful for comminuted fractures or fractures with very small distal fragments in which conventional reduction and fixation is difficult. Aim of the Work to evaluate the treatment of acute acromioclavicular joint dislocation and radiographic outcomes. Materials and Methods Studies were considered eligible if they expressed treatment of acromioclavicular joint dislocation using the hook plate and described the patient's clinical and functional outcomes; intra-operative, post-operative complications, full-text articles were available, randomized controlled trials, including cluster RCTs, controlled (non-randomized) clinical trials or cluster trials, prospective and retrospective comparative cohort studies, and case-control or nested case-control studies. We will exclude cross-sectional studies, case series, case reports and literature not in English. All items that didn't match the above criteria were excluded. Results The total studies included 270 patients with average mean age 35.5 years and mean follow up 25.33 months. The Constant Murely score average 84 points (The CMS was developed for the evaluation of shoulder function with subjective and objective components) and the p value &amp;lt;.05 that means all patients had significant improvement. Full range of motion could be achieved in the patients. Patients with restrictions of range of motion mainly showed limitations in abduction and external rotation. These limitations are most probably caused by the post-operative immobilization, which is necessary after implantation of hook plates to ensure healing of the ligament structures and avoid damage of the acromion by the hook itself. Other studies also showed restrictions of range of motion for abduction and external rotation after hook plate implantation. Conclusion it has a good to excellent Constant Murely score (full range of motion) that enables quick return to activities. It is useful for (Rockwood III-VI). So good clinical results can be achieved with hook plate.

Defying gravity and gadget numerosity: The complexity of the Hanano Puzzle and beyond

Using the notion of visibility representations, our paper establishes a new property of instances of the Nondeterministic Constraint Logic (NCL) problem (a PSPACE-complete problem that is very convenient to prove the PSPACE-hardness of reversible games with pushing blocks). Direct use of this property introduces an explosion in the number of gadgets needed to show PSPACE-hardness, but we show how to bring that number from 32 down to only three in the general case, and down to two in our specific case! We propose it as a step towards a broader and more general framework for studying games with irreversible gravity, and use this connection to guide an indirect polynomial-time many-one reduction from the NCL problem to the Hanano Puzzle—which is NP-hard—to prove it is PSPACE-complete.