Speed Of Regeneration Research Articles

A Cryo-CMOS 10-bit 60-MS/s SAR ADC with common-mode variation suppression switching scheme and gain boosting dynamic comparator

This paper presents a 10-bit 60-MS/s SAR ADC using an energy-efficient common-mode variation suppression (CMVS) switching scheme. The proposed CMVS switching scheme reduces energy consumption by about 92 % compared to the conventional scheme. Also, it narrows the common-mode variation to 16.6 % VDD. It improves the accuracy of the SAR ADC and makes the comparator and SAR ADC operate at the best-performance region. The proposed comparator adopts a gain boosting dynamic capacitive pre-amplifier to enhance the amplification and accelerate the comparison speed. The regeneration latch keeps the cross-coupled inverter structure to ensure high-speed regeneration. The input pair of the latch suppresses the through current while decreasing the regeneration speed. Therefore, an auxiliary input pair is added to enhance the regeneration speed. The SAR ADC is designed and simulated using 65-nm Cryo-CMOS technology with VDD = 1.2 V. At T = 300 K, it achieves a FoM of 15.39 fJ/conversion-step with 55-MS/s. At T = 4 K, it achieves a FoM of 14.15 fJ/conversion-step with 60-MS/s.

Energy Performance of Zeolite-Based Drying Bead Desiccants Used to Dry Paddy Rice.

This study utilizes differential scanning calorimetry and thermogravimetric analysis to assess the total energy required to regenerate saturated zeolite-based drying beads (DBs) used to dry paddy rice. We quantify the required heat energy for DB regeneration by calculating the area under the curve in a heat flow rate versus time graph, with the end of the regeneration process indicated by stabilization of the DB weight. Our findings suggest that at DB regeneration temperatures ranging from 120 to 350 °C, the process varied from 813 to 22 min, demonstrating that higher temperatures lead to faster regeneration speeds. The total energy used for regeneration showed similar values at 250 and 350 °C, averaging around 2032 and 2136 kJ per kg of dried DB, respectively. Additionally, the study showed that DBs can hold water between 28.7% and 54.4% higher than the manufacturer's specifications, suggesting a reduced quantity of DBs required for effective paddy rice drying. The overall required heat energy for the regeneration process was calculated at 4.86 MJ/kg, with a carbon intensity of approximately 275.61 g of CO2-eq per kg of water removed, resulting in lower values compared to conventional drying methods. The study underscores DB's possibility of lower total energy (thermal and electrical) consumption and greenhouse gas emissions, alongside its flexibility to regenerate with intermittent energy sources.

In-depth Clinical, Haemodynamic and Volumetric Assessment of the RAPID-type Auxiliary Liver Transplantation in Non-cirrhotic Setting; are we Simply Dealing with a Transplant Model of ALPPS?

The RAPID (Resection And Partial Liver Transplantation with Delayed total hepatectomy) procedure involves left hepatectomy with orthotopic implantation of a left lobe and right portal vein ligation. This technique induces volumetric graft increase, allowing for a right completion hepatectomy within 15 days. Notably, there is a lack of data on the hemodynamics of Small-for-Size (SFS) grafts exposed to portal overflow without triggering SFS syndrome. A prospective single-center protocol included eight living donors and eight RAPID non-cirrhotic recipients. Comprehensive clinical and biological data were collected, accompanied by intraoperative arterial and portal flow and pressure measurements. Early kinetic growth rate (eKGR%) and graft function were assessed using CT and 99Tc-mebrofenin scintigraphy on postoperative days 7 and 14. Findings were compared with retrospective data from13 left Living Donor Liver Transplantation (LDLT) recipients. The median Graft-body weight ratio was 0.41% (IQR, 0.34 to 0.49), markedly lower than in LDLT. However, there was no significant difference in eKGR between RAPID and LDLT grafts. Sequential analysis revealed variable eKGR per day: 10.6% (7.8-13.2) in the first week and 7.6% (6-9.1) in the second week post-transplantation. Indexed portal flow (iQpv) was significantly higher in RAPID compared to left LDLT (P=0.01). No hemodynamic parameters were found to correlate with regeneration speed. We modulated portal flow in 2 out of 8 cases. This study presents the first report of hemodynamic and volumetric data for the RAPID technique. Despite initial graft volumes falling below conventional LDLT recommendations, the study highlights acceptable clinical outcomes.

Growth patterns of caudal fin rays are informed by both external signals from the regenerating organ and remembered identity autonomous to the local tissue

Regenerating tissues must remember or interpret their spatial position, using this information to restore original size and patterning. The external skeleton of the zebrafish caudal fin is composed of 18 rays; after any portion of the fin is amputated, position-dependent regenerative growth restores each ray to its original length. We tested for transcriptional differences during regeneration of proximal versus distal tissues and identified 489 genes that differed in proximodistal expression. Thyroid hormone directs multiple aspects of ray patterning along the proximodistal axis, and we identified 364 transcripts showing a proximodistal expression pattern that was dependent on thyroid hormone context. To test what aspects of ray positional identity are directed by extrinsic environental cues versus remembered identity autonomous to the tissue, we transplanted distal portions of rays to proximal environments and evaluated regeneration within the new location. Native regenerating proximal tissue showed robust expression of scpp7, a transcript with thyroid-regulated proximal enrichment; in contrast, regenerating rays originating from transplanted distal tissue showed reduced (distal-like) expression during outgrowth. These distal-to-proximal transplants regenerated far beyond the length of the graft itself, indicating that cues from the proximal environment promoted additional growth. Nonetheless, these transplants initiated regeneration at a much slower rate compared to controls, suggesting memory of distal identity was retained by the transplanted tissue. This early growth retardation caused rays that originated from transplants to grow noticeably shorter than neighboring native rays. While several aspects of fin ray morphology (bifurcation, segment length) were found to be determined by the environment, we found that both regeneration speed and ray length are remembered autonomously by tissues, and that persist through multiple rounds of amputation and regeneration.

Pleiotropic effects of nitric oxide sustained-release system for peripheral nerve repair

The regenerative microenvironment after peripheral nerve injury is imbalanced and difficult to rebalance, which is mainly affected by inflammation, oxidative stress, and inadequate blood supply. The difficulty in remodeling the nerve regeneration microenvironment is the main reason for slow nerve regeneration. Traditional drug treatments have certain limitations, such as difficulty in penetrating the blood-nerve barrier and lack of pleiotropic effects. Therefore, there is an urgent need to build multifunctional nerve grafts that can effectively regulate the regenerative microenvironment and promote nerve regeneration. Nitric oxide (NO), a highly effective gas transmitter with diatomic radicals, is an important regulator of axonal growth and migration, synaptic plasticity, proliferation of neural precursor cells, and neuronal survival. Moreover, NO provides potential anti-inflammation, anti-oxidation, and blood vessel promotion applications. However, excess NO may cause cell death and neuroinflammatory cell damage. The prerequisite for NO treatment of peripheral nerve injury is that it is gradually released over time. In this study, we constructed an injectable NO slow-release system with two main components, including macromolecular NO donor nanoparticles (mPEG-P(MSNO-EG) nanoparticles, NO-NPs) and a carrier for the nanoparticles, mPEG-PA-PP injectable temperature-sensitive hydrogel. Due to the multiple physiological regulation of NO and better physiological barrier penetration, the conduit effectively regulates the inflammatory response and oxidative stress of damaged peripheral nerves, promotes nerve vascularization, and nerve regeneration and docking, accelerating the nerve regeneration process. Statement of significanceThe slow regeneration speed of peripheral nerves is mainly due to the destruction of the regeneration microenvironment. Neural conduits with drug delivery capabilities have the potential to improve the microenvironment of nerve regeneration. However, traditional drugs are hindered by the blood nerve barrier and cannot effectively target the injured area. NO, an endogenous gas signaling molecule, can freely cross the blood nerve barrier and act on target cells. However, excessive NO can lead to cell apoptosis. In this study, a NO sustained-release system was constructed to regulate the microenvironment of nerve regeneration through various pathways and promote nerve regeneration.

Early corticosteroid treatment enhances recovery from SARS-CoV-2 induced loss of smell in hamster

Among the numerous long COVID symptoms, olfactory dysfunction persists in ∼10 % of patients suffering from SARS-CoV-2 induced anosmia. Among the few potential therapies, corticoid treatment has been used for its anti-inflammatory effect with mixed success in patients. In this study, we explored its impact using hamster as an animal model. SARS-CoV-2 infected hamsters lose their smell abilities and this loss is correlated with damage of the olfactory epithelium and persistent presence of innate immunity cells. We started a dexamethasone treatment 2 days post infection, when olfaction was already impacted, until 11 days post infection when it started to recover. We observed an improvement of olfactory capacities in the animals treated with corticoid compared to those treated with vehicle. This recovery was not related to differences in the remaining damage to the olfactory epithelium, which was similar in both groups. This improvement was however correlated with a reduced inflammation in the olfactory epithelium with a local increase of the mature olfactory neuron population. Surprisingly, at 11 days post infection, we observed an increased and disorganized presence of immature olfactory neurons, especially in persistent inflammatory zones of the epithelium. This unusual population of immature olfactory neurons coincided with a strong increase of olfactory epithelium proliferation in both groups. Our results indicate that persistent inflammation of the olfactory epithelium following SARS-CoV-2 infection may alter the extent and speed of regeneration of the olfactory neuron population, and that corticoid treatment is effective to limit inflammation and improve olfaction recovery following SARS-CoV-2 infection.

Investment in regeneration versus asexual reproduction is resource‐dependent in a freshwater annelid

Abstract The post‐embryonic developmental processes of regeneration and asexual agametic reproduction are widespread and often co‐occur in animals. These traits are of great ecological significance, but their physiological dynamics within species are not well understood. In naid annelids, regeneration and asexual reproduction via fission are evolutionarily related and mechanistically similar yet distinct, making these animals useful systems in which to study resource allocation strategies between the two processes. How asexual reproductive investment varies as a function of somatic investment demands was tested in the naid Pristina leidyi by repeatedly amputating the heads of individual worms, allowing regeneration to proceed, and measuring reproductive output over time. Treatments were replicated under high and low food levels to determine to what extent the investment dynamic between regeneration and fission is affected by the resource pool. Reproductive output was affected by injury and regeneration frequency in a resource‐dependent manner, such that only worms with less food availability exhibited reproductive deficits; injury and regeneration did not affect reproductive output of worms under the high food condition. When reproductive output was decreased, this occurred not through a reduction in offspring quantity but a reduction in offspring quality. In the offspring of experimental animals, body size and fission speed were dependent on parental feeding level and to a lesser and inconsistent extent on parental injury history, but regeneration speed was unaffected by parental treatment. These findings suggest that, in a species capable of both regeneration and asexual reproduction: (1) the resource pool is a key factor mediating the resource investment pattern between regeneration and fission; (2) sacrificing per‐offspring investment rather than fecundity may be an optimal strategy if resources are limiting; (3) regeneration and fission have evolved distinct resource allocation pathways. This work prompts further questions about the physiological dynamics between regeneration and asexual reproduction in animals, such as whether and to what extent these have evolved adaptively, including in response to injury and resource pressures. Read the free Plain Language Summary for this article on the Journal blog.

Dental Biopolymer Composites with Antibiotics, Bisphosphonate, and Hydroxyapatite for Possible Use in Bone Tissue Regeneration

The aim of the present study was to formulate new variants of synthetic and animal-source bone materials coated with different biopolymers, containing antibiotics (ampicillin and oxacillin) and alendronate drugs. Validation consists in establishing mixtures that do not present interactions between components. These materials should act as a drug delivery system alongside the bone base. Natural polymers such as chitosan, alginate, and kappa-carrageenan have been shown to be optimal materials for drug delivery due to their intrinsic biocompatibility. Binary, ternary, and quaternary mixtures between components are analyzed by FT-IR spectroscopy, UV-Vis analysis, thermogravimetry (TGA), and scanning electron microscopy (SEM). The analysis led to the validation of materials suitable for the controlled release of active substances, which have the greatest chance of increasing the speed of bone regeneration, as well as helping in the local administration of antibiotics, which currently must be administered in the form of oral formulations or an injection. According to the FTIR, thermogravimetry, UV-Vis, SEM, and cytotoxicity tests performed in this study, it can be said that it is quite easy to obtain materials that can be used in dental practice that facilitate bone reconstruction through local treatment. At the same time, it was found that both active substances can be incorporated into the material together with Alg and Chit, thus limiting the adverse effects and maximizing the local beneficial effects.

The role of the ImmunatuRNA® complex in promoting skin immunity and its regenerative abilities: Implications for antiaging skincare.

Recent advancements in cosmetic science have ushered in a new era of skincare strategies, with a focus on utilizing natural bioactive ingredients to enhance skin health and combat premature aging. The skin, as the largest organ of human body, provides as a vital protective barrier against external hazards such as environmental pollutions, toxins, and radiation. However, intrinsic and extrinsic factors, including various types of radiation, reduced air quality, and increased exposure to pollutants, lead to an imbalance in the skin's immune system, significantly reducing the skin's ability to regenerate and accelerating skin aging. Therefore, there is an emerging need to develop innovative skincare strategies that could support the skin's immune capacity by strengthening antioxidant protection, skin regeneration, and repair. Plant-derived compounds, along with naturally sourced ingredients, show promise in accelerating wound healing, especially when incorporated into cosmetic formulation. ImmunatuRNA® stands as a prime example of a biologically active complex, uniquely comprising yeast-derived RNA, marine exopolysaccharides, and natural hyaluronic acid, that exhibits high antioxidant activity and exerts beneficial modulatory effects on skin microbiota, thereby positively influencing skin immunity. The main aim of this study was to investigate the potential of the ImmunatuRNA® complex in promoting skin regeneration and reducing signs of skin aging, both through the use of invitro human skin cultures and the evaluation of clinical trials in healthy volunteers. The results of conducted experimental studies have shown that the ImmunatuRNA® complex demonstrated significant positive effects on the immunity and repair capabilities of the skin, characterized by increased fibroblast proliferation, enhanced glycosaminoglycan synthesis, and reduced oxidative stress. Furthermore, use of the complex also significantly accelerated wound healing following mechanically-induced damage in the keratinocytes, demonstrated as reduction in wound margins measurement, new cell production, and an increase in regeneration speed. In addition, conduced clinical study on healthy human volunteers with various skin types confirmed that use of cosmetic products that incorporate the ImmunatuRNA® complex within the formulation can visibly improve skin condition, appearance, and general health, achieved by increased skin hydration and elasticity, reduced wrinkles, and enhanced skin firmness. This study confirms the usefulness of the ImmunatuRNA® complex in the innovative antiaging cosmetic products that can be suitable for all skin types, including sensitive skin. The inclusion of naturally sourced bioactives, as those found in ImmunatuRNA® complex, represents a promising advancement in holistic natural skincare that consumers appreciate. The active ingredients of the complex support the skin's immunity, fostering its repair and protecting against oxidative damage, thus maintaining skin homeostasis and promoting its regenerative capacity. Further research is necessary to explore the long-term effects of ImmunatuRNA® complex on skin health and its potential applications in innovative skincare formulations.

Tail regeneration at different ontogenetic stages of the tiger salamander Ambystoma tigrinum suggests possible changes in regeneration between larval and metamorphic individuals

AbstractUrodele amphibians possess remarkable regenerative abilities, allowing them to rebuild lost body parts. Contrary to lizards, salamanders can fully restore their tails, including the neural spine and components of the vertebral column. The axolotl (Ambystoma mexicanum) is the vertebrate model organism for regeneration research due to its ease of breeding in captivity. However, axolotls are paedomorphic, retaining larval somatic features throughout adulthood and do not naturally undergo metamorphosis, a transition phase from aquatic larvae to terrestrial adults with profound morphological and physiological changes. We investigate the influence of metamorphosis on salamander tail regeneration after conspecific biting in the metamorphosing sister taxon Ambystoma tigrinum using histological analysis to answer two key questions: (1) Does regeneration continue during metamorphosis, or is it halted? (2) How does regeneration differ histologically among larval, metamorphosing and postmetamorphic individuals? Our findings demonstrate that regeneration continues even during metamorphic climax, indicating the simultaneous coordination of metamorphosis and regeneration. Additionally, notable distinctions were observed between developmental stages concerning the speed of regeneration and structural differences in the formation of an apical epithelial cap (AEC). While the approach taken in this study necessarily restricts sample size, it offers valuable insights into regeneration in a metamorphosing species under natural conditions.

Investigation of the mechanisms for wireless nerve stimulation without active electrodes.

Electric-field stimulation of neuronal activity can be used to improve the speed of regeneration for severed and damaged nerves. Most techniques, however, require invasive electronic circuitry which can be uncomfortable for the patient and can damage surrounding tissue. A recently suggested technique uses a graft-antenna-a metal ring wrapped around the damaged nerve-powered by an external magnetic stimulation device. This technique requires no electrodes and internal circuitry with leads across the skin boundary or internal power, since all power is provided wirelessly. This paper examines the microscopic basic mechanisms that allow the magnetic stimulation device to cause neural activation via the graft-antenna. A computational model of the system was created and used to find that under magnetic stimulation, diverging electric fields appear at the metal ring's edges. If the magnetic stimulation is sufficient, the gradients of these fields can trigger neural activation in the nerve. In-vivo measurements were also performed on rat sciatic nerves to support the modeling finding that direct contact between the antenna and the nerve ensures neural activation given sufficient magnetic stimulation. Simulations also showed that the presence of a thin gap between the graft-antenna and the nerve does not preclude neural activation but does reduce its efficacy.

Shoot Culture of Ocimum sp. and Its Phytochemical Profile

The success of the in vitro culture technique is influenced by many factors, including the type of explants, culture medium and exogenous plant growth regulators (PGR). These factors greatly influence the speed and effectiveness of plant regeneration as well as the profile of the phytochemical compounds produced. Therefore, this study aims to determine the effect of the PGR combination on the growth response of in vitro node explants as well as the phytochemical profiles of Ocimum sp. Node explants obtained from 2 weeks old in vitro seedlings were cultured on MS medium with the addition of PGR, namely BAP and Kinetin (0.2 and 5 mg/l) combined with NAA (0.1 and 0.2 mg/l) and synthetic cytokinins alone namely Thidiazuron (TDZ) (1, 3, and 5 mg/l). The growth response of the explants and the potential for regeneration were observed for 8 weeks of culture. Effects of adding activated charcoal (AC) to root media were observed on growth of plantlets aged 2 weeks. Phytochemical profile of In vitro shoot was analyzed using GC-MS and LC-MS to be compared with its profile in in vitro callus tissue. The results showed that MS medium with the addition of a combination of cytokinin and auxin was able to induce shoot regeneration in node explants of Ocimum sp. in vitro. The Kinetin/NAA combination produced better shoot height growth, while the BAP/NAA combination produced a higher leaves number. Thidiazuron at all concentrations was able to induce shoots that were more likely to form rosettes. The addition of AC to the rooting medium did not have a positive effect on the response of shoot and plantlet growth. Chromatographic screening showed different profiles of secondary compounds in the callus and shoot tissues of Ocimum sp. in vitro. Callus composed of actively dividing cells do not produce some of the secondary compounds as produced by in vitro shoots. This shows the difference in the potential of cells or tissues in synthesizing secondary metabolites.

Analysis of physiological mechanisms of adaptation and resilience of winter wheat accession of different geographical origin

The aim of the study: Analyzing the role of morphotype traits, physiological reactions in adaptation to the conditions of the Left Bank Forest Steppe of Ukraine by studying a wide set of winter wheat collection accessions and identifying valuable samples for further involving them in the local breeding program.
 Materials and methods: The article contains the results of the research of 318 samples of winter wheat of different ecological and geographical origin from 27 countries according to the complex of morphological traits and physiological reactions to the environmental conditions of the Left Bank Forest Steppe of Ukraine in the 2020-2021 and 2021-2022 growing years. A field evaluation (visual score) was carried out at next parameters: evaluation of the state of plants before wintering; assessment of winter hardiness; assessment of the speed of plant regeneration in the spring; fixation of the earing date; assessment damage by foliar diseases. An assessment of morphological traits was carried out in accordance with the methodology for the examination of varieties of common wheat (Triticum aestivum L.) for DUS-test recommended by UPOV and the State Service, the methodology of physiological research in breeding from CIMMYT and the methodology for the selection of winter-hardy wheat genotypes.
 Discussion of the results: Significant variation was found for all studied traits. Analysis of temperature indicators in recent years indicates changes in the passage of the autumn and winter periods of wheat vegetation in the Left Bank Forest-Steppe zone of Ukraine. The weather conditions of both years of the study were generally favorable for the overwintering of winter wheat plants. It is worth noting that the overwintering conditions in the 2021-2022 vegetation year were somewhat more difficult, wheat plants were more exhausted due to the presence of sudden temperature increases and decreases. It has been studying, what important for the wheat plants adaptation to the weather conditions is not only frost resistance, but also winter resistance in combination with a high level of growth in the initial stages and good regeneration at the spring period. A correlation was established between the traits of field winter resistance and the intensity of growth in the autumn period (r=0.653) and with the regenerative capacity of plants in the spring period (r=0.835).
 Conclusions: Selected samples with high winter hardiness and high intensity of spring regeneration - Lira odes’ka, Oberih Myronivskyi, Dykanka (Ukraine) and varieties of foreign origin - Turkuaz (Azerbaijan) and Andrada (Romania). The following samples had increased winter hardiness (7-8 points) and good regeneration in spring (8-9 points) - Oktava odes’ka, Natalka, Zolotava Nosivska, Lehenda Myronivska, Bunchuk, Orzytsia Nova, PS Tashan’ (Ukraine), T67/X84W063-9-45//Karl92/3 (Turkey), AR800-1-3-1/NW97S320, NE10507 (USA). According to the two years results of the evaluation of the resistance of genotypes to Septoria tritici blotch, next samples can be use as resistance sources - Kraevyd, Mahnatka, Spivanka poliska (Ukraine), Arctis (Germany), Apertus (Austria), AR800-1-3- 1/NW97S320 (USA).

A doubled transistor latch common-mode insensitive rail-to-rail regenerative comparator for low supply voltage applications

This paper presents a high-speed common-mode insensitive two-stage regenerative comparator designed for low supply voltage applications. The proposed comparator features a doubled transistor latch that enables rail-to-rail operation, which is pioneered to the best of the author's knowledge. The voltage swing of output nodes of the pre-amplifiers is limited to reduce the power consumption. This limitation boosts the regeneration speed of the doubled transistor latch. The proposed comparator realized by a standard 65 nm CMOS technology. The post-layout simulation results corroborate that the proposed comparator with 50 MHz sample rate and 0.6 V supply voltage dissipates 3.4 µW power, and occupies 168 µm2 area. Also, the offset voltage variation within the full common-mode range can be below 2 mV. In a worst-case scenario compared to the conventional single-stage comparator, the proposed comparator improves delay and energy efficiency by more than 80%. Considering its overall performance, this energy-efficient comparator is suitable for all low supply voltage applications, including Internet of Things (IoT), successive approximation registers analog-to-digital converters (SAR ADCs), and biomedical implants.

High-efficient cyclic absorption of sulfur dioxide in Na-Mg-Ci3- compound system for wet flue gas desulfurization

Sulfur dioxide (SO2), as a primary pollutant in the air, has attracted much attention due to the adverse effects on the atmospheric environment and human health. The wet flue gas desulfurization (WFGD) has been proved to be the most effective method to control the emission of SO2. However, the traditional absorbents in WFGD posed the problems of limited recycling utilization and susceptible to oxidation. In this study, we proposed the Na-Mg-Ci3- compound system to repeatedly absorb SO2 for rounds. The results demonstrated that the compound system can integrate the absorption capacity of Na3Ci absorbent and the regeneration efficiency of Mg3Ci2 absorbent. We compared the performances of the compound systems with different alkaline earth metals (Li, Na, K), and the sodium was most suitable for the circulating desulfurization with the consideration of performance and economy. After that, we investigated the influence of ingredient proportions on the absorbent performance, and the results showed that the 0.4 mol/L Na3Ci and 0.2 mol/L Mg3Ci2 were the best combination for the compound system in these experiments. In this condition, the compound system had the excellent effective sulfur capacity and regeneration speed in the recycling process. Moreover, the anti-oxidation effect of sodium ascorbate was explored, and the reusability performance of compound system can be improved with antioxidants. This study contributes to providing a novel method for the removal and recycling of SO2 in the wet flue gas desulphurization.

Land abandonment as driver of woody vegetation dynamics in Tamaulipan thornscrub at Northeastern Mexico.

Vegetation structure is defined as the temporal and spatial distribution of plant species in a particular site. Vegetation structure includes vertical and horizontal distribution and has been widely used as an indicator of successional changes. Ecological succession plays an essential role in the determination of the mechanisms that structure plant communities under anthropogenic disturbances. After an anthropogenic disturbance, such as grazing, forests follow changes in the original composition and vegetation structure, which eventually could restore some of their attributes to become mature forests again. To know how the time of abandonment affects woody plant communities, we ask the following questions: (1) How does the species richness, diversity, and vertical structure (A index) change concerning the time of abandonment? (2) Are species similarities among woody vegetation communities determined by land abandonment? (3) Which woody species have the highest ecological importance in each successional stage? We explored how successional stages after land abandonment mediated the species richness, species diversity (alpha and beta), and ecological importance value index on four areas of Tamaulipan thornscrub. We selected four areas that differed in time of abandonment: 10, 20, 30, and >30 years. The first three areas were used for cattle grazing, whereas the >30-year area was selected as a control since it does not have a record of disturbance by cattle grazing or agriculture. During the summer of 2012, we randomly established four square plots (40 m × 40 m) in each area, separated at least 200 m from each other. In each plot, we recorded all woody individuals per species with a basal diameter ≥1 cm at 10 cm above ground level. We estimated species richness indices, species diversity (alpha and beta), and ecological importance value index. We recorded 27 woody species belonging to 23 genera and 15 families. Fabaceae accounted for 40% of the species. Acacia farnesiana was the most important and abundant species in the first three successional stages. We suggested that older successional stages of Tamaulipan thornscrub promote woody plant communities, characterized by a higher complex structure than younger communities. We observed the highest species similarity between the sites with a closer time of abandonment, while the lowest similarity was shown between the sites with extreme time of abandonment. We conclude that Tamaulipan thornscrub shows a similar trend of ecological succession to other dry forests and the time of abandonment has a high mediation on plant dynamics in the Tamaulipan thornscrub. Also, we stand out the importance of secondary forests for Tamaulipan thornscrub woody plant communities. Finally, we recommended future studies include aspects of regeneration speed, the proximity of mature vegetation, and the interactions of plants with their seed dispersers.

Aligned core–shell fibrous nerve wrap containing Bletilla striata polysaccharide improves functional outcomes of peripheral nerve repair

Peripheral nerve injuries are commonly encountered in extremity traumas. Their motor and sensory recovery following microsurgical repair is limited by slow regeneration speed (<1 mm/d) and subsequent muscle atrophy, which are consequently correlated with the activity of local Schwann cells and efficacy of axon outgrowth. To promote post-surgical nerve regeneration, we synthesized a nerve wrap consisting of an aligned polycaprolactone (PCL) fiber shell with a Bletilla striata polysaccharide (BSP) core (APB). Cell experiments demonstrated that the APB nerve wrap markedly promoted neurite outgrowth and Schwann cell migration and proliferation. Animal experiments applying a rat sciatic nerve repair model indicated that the APB nerve wrap restored conduction efficacy of the repaired nerve and the compound action potential as well as contraction force of the related leg muscles. Histology of the downstream nerves disclosed significantly higher fascicle diameter and myelin thickness with the APB nerve wrap compared to those without BSP. Thus, the BSP-loaded nerve wrap is potentially beneficial for the functional recovery after peripheral nerve repair and offers sustained targeted release of a natural polysaccharide with good bioactivity.

Challenges in post-earthquake recovery of damaged and neglected buildings in Christchurch CBD

More than a decade since the 22 February 2011 earthquake devastated Christchurch CBD, partially demolished and neglected buildings remain present in the post-earthquake landscape. Christchurch City Council has made significant progress in recent years to reduce the level of neglected buildings across the central parts of the city. To encourage remediation of these buildings, the Council initiated the Barrier Sites programme to keep track of central city sites. This paper documents the current inventory of derelict properties and investigates issues that are delaying progress on these sites. We explore regulatory levers that can be used to influence action on these buildings (e.g. provisions in the Building Act and council bylaws). We also investigate how the local market drivers influence the speed of regeneration. Our review identifies gaps in the regulatory powers to act on barrier sites. Taking action involves meeting difficult definitions and tests under legislation and/or taking court proceedings. Specific legislative tools are needed to provide Councils with the powers they need to ensure action is taken on barrier sites to progress the regeneration of the city after a disaster. We also find that the delays in removing the cordon and uncertainties of the public sector anchor projects contained in the Blueprint have led to the loss of private investment and forced central city developments compete with more affordable commercial and residential offerings outside the CBD. With the passing of the 10-year anniversary of the earthquakes, this project offers a timely reminder of the mammoth struggles that the city has overcome evident in the numerous modern and resilient buildings, yet a few ‘battle sites’ slow the much-needed regeneration towards a resilient city centre.

The additive effects of bioactive glasses and photobiomodulation on enhancing bone regeneration.

Bioactive glasses (BG) have been generally used in bone defects repair for its good osteoinductivity and osteoconductivity. However, the early angiogenesis of BG in the repair of large-sized bone defects may not be sufficient enough to support new bone formation, resulting in the failure of bone repair. Photobiomodulation (PBM) therapy, which is superior on promoting early angiogenesis, may contribute to the angiogenesis of BG and further enhance the repair of bone defects. Therefore, we applied BG and PBM in combination and preliminarily investigated their additive effects on bone regeneration both in vitro and in vivo. The in vitro results revealed that BG combined with PBM remarkably enhanced human bone marrow mesenchymal stem cells proliferation, osteogenic-related genes expression and mineralization, which was better than applying BG or PBM respectively. For in vivo studies, the histological staining results showed that BG induced new bone formation in the interior of defects and promoted new bone reconstruction at 6 weeks post-operation. The micro-computed tomography results further confirmed that BG combined with PBM accelerated bone formation and maturation, improved the speed and quality of bone regeneration, and promoted bone repair. In conclusion, with the optimum BG and PBM parameters, BG combined with PBM generated additive effects on promoting bone regeneration.

Succinic Ester-Based Shape Memory Gelatin Sponge for Noncompressible Hemorrhage without Hindering Tissue Regeneration.

Shape memory sponges are very promising in stopping the bleeding from noncompressible and narrow entrance wounds. However, few shape memory sponges have fast degradable properties in order to not hinder tissue healing. In this work, based on cryopolymerization, a succinic ester-based sponge (Ssponge) is fabricated using gelatin and bi-polyethylene glycol-succinimidyl succinate (Bi-PEG-SS). Compared with the commercially available gelatin sponge (Csponge), Ssponge possesses better water/blood absorption ability and higher mechanical pressure over the surrounding tissues. Moreover, in the models of massive liver hemorrhage after transection and noncompressive liver wounds by penetration, Ssponge exhibits a better hemostasis performance than Csponge. Furthermore, in a liver regeneration model, Ssponge-treated livers shows higher regeneration speed compared with Csponge, including a lower injury score, more cavity-like tissues, less fibrosis and enhanced tissue regeneration. Overall, it is shown that Ssponge, with a fast degradation behavior, is not only highly efficient in stopping bleeding but also not detrimental for tissue healing, possessing promising clinical translational potential.