Paradoxical Embolism in Juveniles and Young Adults With Severe-to-Profound Sudden Sensorineural Hearing Loss.

Objective: Paradoxical embolism from right-to-left shunting is a common cause of cryptogenic stroke in the young. Circulatory ischemia of the cochlea is closely connected with severe-to-profound sudden sensorineural hearing loss. This study aimed to explore the role of paradoxical embolism in severe-to-profound sudden sensorineural hearing loss in juveniles and young adults. Methods: From August 2021 to September 2022, consecutive outpatients under 35 years of age with severe-to-profound sudden hearing loss were included in the study. Routine auditory electrophysiological testing and contrast transcranial Doppler ultrasonography (c-TCD) were conducted, and the results were retrospectively analyzed. Results: Seven patients (age: 19.4 ± 6.5 years) were enrolled, including 5 juveniles and 2 young adults. Three patients had severe deafness, and 4 patients had profound deafness. Right-to-left shunting was detected in all patients through c-TCD. Patent foramen ovale was found in 2 patients while pulmonary arteriovenous fistula was found in 1 patient through contrast transthoracic echocardiography or cardiac catheterization. No patients had precipitating factors for sudden sensorineural hearing loss, and none had abnormalities on head magnetic resonance imaging. Six patients underwent whole-exome sequencing, and no known deafness gene variant was detected. After standard treatment for 1 month, 2, 3, and 2 patients had complete, slight, and no hearing recovery, respectively. Conclusions: Paradoxical embolism is a possible cause of severe-to-profound sudden sensorineural hearing loss in juveniles and young adults. In young patients, c-TCD is an effective screening tool to detect right-to-left shunting, while contrast transthoracic echocardiography is a complementary examination to c-TCD.

Enhancement of Nutritional Substance, Trace Elements, and Pigments in Waxy Maize Grains through Foliar Application of Selenite.

Selenium (Se) is a micronutrient known for its essential role in human health and plant metabolism. Waxy maize (Zea mays L. sinensis kulesh)-known for its high nutritional quality and distinctive flavor-holds significant consumer appeal. Therefore, this study aims to assess the effects of foliar Se spraying on the nutritional quality of waxy maize grains, with a focus on identifying varietal differences and determining optimal Se dosage levels for maximizing nutritional benefits. We employed a two-factor split-plot design to assess the nutritional quality, trace elements, and pigment content of jinnuo20 (J20) and caitiannuo1965 (C1965) at the milk stage after being subjected to varying Se doses sprayed on five leaves. Our findings indicate superior nutrient content in J20 compared to C1965, with both varieties exhibiting optimal quality under Se3 treatment, falling within the safe range of Se-enriched agricultural products. JS3 (0.793) demonstrated the highest overall quality, followed by JS2 (0.606), JS4 (0.411), and JS1 (0.265), while CS0 had the lowest (-0.894). These results underscore the potential of foliar biofortification to enhance the functional component contents of waxy maize grains.

Transfer learning for anatomical structure segmentation in otorhinolaryngology microsurgery.

BACKGROUND: Reducing the annotation burden is an active and meaningful area of artificial intelligence (AI) research. METHODS: Multiple datasets for the segmentation of two landmarks were constructed based on 41 257 labelled images and 6 different microsurgical scenarios. These datasets were trained using the multi-stage transfer learning (TL) methodology. RESULTS: The multi-stage TL enhanced segmentation performance over baseline (mIOU 0.6892 vs. 0.8869). Besides, Convolutional Neural Networks (CNNs) achieved a robust performance (mIOU 0.8917 vs. 0.8603) even when the training dataset size was reduced from 90% (30 078 images) to 10% (3342 images). When directly applying the weight from one certain surgical scenario to recognise the same target in images of other scenarios without training, CNNs still obtained an optimal mIOU of 0.6190 ± 0.0789. CONCLUSIONS: Model performance can be improved with TL in datasets with reduced size and increased complexity. It is feasible for data-based domain adaptation among different microsurgical fields.

Unveiling the luminescence property of Li2MgGeO4:Mn4+ featuring the tetrahedral crystallographic-site occupancy of Mn4.

Owing to the occupying tendency of Mn4+ at octahedral sites, doping Mn4+ activators in tetrahedral structures poses challenges and hence is seldom reported. In this work, tetrahedrally sited Mn4+ phosphors were studied. By combining X-ray diffraction (XRD) data with Rietveld refinement analysis, the location of Mn4+ was determined. It was found that by adding excessive raw MgO, the phosphor synthesis temperature can be improved, enhancing the crystallinity of the crystal and thus improving the emission performance of the phosphor. In addition, excessive raw MgO forms a second phase in an LMGO matrix, which does not change the doping site for Mn4+. The Tanabe-Sugano diagram of Mn4+ in the tetrahedral field and the energy-level diagram of these phosphors were constructed for the first time, and the excitation and emission mechanisms are discussed in detail. With 1.2-fold excess of raw MgO, the prepared sample (LMGO-Mn-1.2) shows the best luminescence, demonstrating red emissions peaked at 656 nm and affording an emission intensity enhancement of over 50 times compared to a stoichiometric LMGO:Mn4+ system. At 150 °C, LMGO-Mn-1.2 keeps 90% emission intensity compared to that at room temperature. Finally, a high-efficiency warm white light-emitting diode was built. This work provides new insights into the study of Mn4+-activated phosphors in a tetrahedron crystal field.

GNB4 Silencing Promotes Pyroptosis to Inhibit the Development of Glioma by Activating cGAS-STING Pathway.

The induction of immunogenic cell death is a promising therapeutic option for gliomas. Pyroptosis is a type of programmed immunogenic cell death and its role in gliomas remains unclear. Differentially expressed genes (DEGs) were obtained from GSE4290 and GSE31262 datasets. Hub genes were screened from protein-protein interaction networks and assessed using principal component analysis and receiver operating characteristic curves. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the mRNA expression of hub genes. Pyroptosis and pathway-related proteins were assessed using western blotting. Inflammatory factor levels were determined using enzyme-linked immunosorbent assay. The effect of guanine nucleotide-binding protein-4 (GNB4) on proliferation, migration, and invasion was evaluated using a cell viability test kit and wound-healing and transwell assays. In total, 202 DEGs were identified. Among them, F2R, GNG4, GNG3, PRKCB, and GNB4 were identified as hub genes in gliomas after comprehensive bioinformatics analysis. GNB4 was significantly upregulated in glioma cells compared to normal brain glial cells. Silencing GNB4 significantly inhibited proliferation, invasion, and migration of glioma cells. The expression of pyroptosis-related proteins increased after GNB4 silencing, with elevated levels of inflammatory factors. Pyroptosis inhibitors reversed the inhibitory effects of GNB4 silencing on cell proliferation, migration, and invasion. Additionally, GNB4 silencing activated the cGAS-STING pathway. Treatment with a cGAS-STING pathway inhibitor reversed the inhibition of proliferation, migration, and invasion while downregulating the expression of pyroptosis-related proteins. Silencing GNB4 promotes pyroptosis and thus inhibits the proliferation, migration, and invasion of glioma cells by activating the cGAS-STING pathway, which is a promising biomarker and therapeutic target for glioma.

Relationship between intervertebral disc height and post operative dysphagia secondary to single-level anterior cervical discectomy and fusion- a retrospective study.

BACKGROUND: One goal of Anterior Cervical Discectomy and Fusion (ACDF) is to restore the loss of intervertebral disc height (IDH) results from the degenerative process. However, the effects of IDH on postoperative dysphagia after ACDF remain unclear. METHODS: Based on the results of a one-year telephone follow-up, A total of 217 consecutive patients after single-level ACDF were enrolled. They were divided into dysphagia and non-dysphagia groups. The age, BMI, operation time and blood loss of all patients were collected from the medical record system and compared between patients with and without dysphagia. Radiologically, IDH, spinous process distance (SP) of the operated segment, and C2-7 angle (C2-7 A) were measured preoperatively and postoperatively. The relationship between changes in these radiological parameters and the development of dysphagia was analyzed. RESULTS: Sixty-three (29%) cases exhibited postoperative dysphagia. The mean changes in IDH, SP, and C2-7 A were 2.84 mm, -1.54 mm, and 4.82 degrees, respectively. Changes in IDH (P = 0.001) and changes in C2-7 A (P = 0.000) showed significant differences between dysphagia and non-dysphagia patients. Increased IDH and increased C2-7 A (P = 0.037 and 0.003, respectively) significantly and independently influenced the incidence of postoperative dysphagia. When the change in IDH was ≥ 3 mm, the chance of developing postoperative dysphagia for this patient was significantly greater. No significant relationship was observed between the change in spinous process distance (SP) and the incidence of dysphagia. The age, BMI, operation time and blood loss did not significantly influence the incidence of postoperative dysphagia. CONCLUSION: The change in IDH could be regarded as a predictive factor for postoperative dysphagia after single-level ACDF.

[Analysis of the effect of different facial nerve managements applied to tumor resection in the jugular foramen region].

Objective:To summarize the results of different facial nerve management modalities applied to tumor resection in the jugular foramen region. Methods:The clinical data of 54 patients with tumors in the jugular foramen region who underwent surgery from January 2015 to March 2023 were retrospectively analyzed: 18 males and 36 females; Age ranges from 21 to 67 years, with an average age of 44.4 years; and median follow-up time: 12 months. The House-Brackmann（HB） grading system was applied to assess the patients' facial nerve function before surgery, 1-2 weeks after surgery and at the final follow-up （HBⅠ-Ⅱ grade for good function）: 42 cases with preoperative HB grades Ⅰ-Ⅱ; partial facial nerve transposition（9 cases）, complete facial nerve transposition（28 cases）, and facial nerve excision and re-construction（17 cases） were used, respectively（stage Ⅰor Ⅱ）. Relevant factors affecting postoperative facial nerve function were analyzed. Results:Postoperative pathology confirmed 39 cases of paraganglioma, 9 cases of nerve sheath tumor, 3 cases of meningioma, and 1 case each of fibromucinous sarcoma, chondrosarcoma, and intravascular myofibroma. Facial nerve function after partial facial nerve transposition was HB grade Ⅰ-Ⅱ in 89%（8/9）; after complete facial nerve transposition was HB grade Ⅰ-Ⅱ in 86%（24/28） in 28 cases; after facial nerve severance and reconstruction was HB grade Ⅰ-Ⅱ in 2/7（Stage Ⅰ） and 0/3（Stage Ⅱ）, respectively. Tumor size and surgical approach were correlated with postoperative facial nerve function in patients with facial nerve transposition（P<0.05）. There was no statistically significant difference in facial nerve function after complete and partial facial nerve transposition（P>0.05）. Conclusion:Intraoperative stretching of the facial nerve may be an important factor affecting facial nerve function during surgical treatment of tumors in the jugular venous foramen region; for patients with facial nerve dissection, facial nerve reconstruction should be adopted according to the situation, aiming at the recovery of facial nerve function.

[The assessment of facial nerve function].

The assessment of facial nerve function plays a crucial role in the diagnosis and treatment of facial nerve disorders.The assessment system for facial nerve function is primarily categorized into subjective and objective systems.While the subjective assessment system is relatively simple, it lacks accuracy as it can be influenced by the subjectivity of evaluator.Whereas, the objective system offers higher precision and stability, providing more quantitative information. In recent years, benefited with advancements in computer vision and artificial intelligence,we have witnessed increasingly accurate,stable and intelligent facial nerve assessment systems gradually implemented in clinical practice.When selecting a specific facial nerve assessment system,factors such as clinical scenarios,assessment objectives,patient characteristics should be considered.

Identification and health risk evaluation of soil contaminated by polycyclic aromatic hydrocarbons at shale gas extraction sites based on positive matrix factorization.

The impact of shale gas extraction on surrounding environmental media remains unclear. In this study, the current state of contamination by polycyclic aromatic hydrocarbons (PAHs), which are high-frequency contaminants of shale gas, was investigated in the soil surrounding emerging shale gas development sites. The source analysis of PAHs was conducted in the soils of shale gas extraction sites using positive matrix factorization (PMF). The health risk assessment (HRA) was calculated for ingestion, dermal contact, and inhalation exposures, and the priority sources of PAHs in the soil were jointly identified by PMF and HRA to refine the contribution level of different individual PAHs to the carcinogenic risk. The results showed that both Sichuan and Chongqing mining site soils were contaminated to different degrees. Shale gas extraction has an impact on the surrounding soil, and the highest contributing source of PAHs in the mining site soil of Sichuan was anthropogenic activity, accounting for 31.6%, whereas that in the mining site soil of Chongqing was biomass combustion and mixed automobile combustion, accounting for 35.9%. At the two mining sites in Sichuan and Chongqing, none of the three exposure pathways (ingestion, dermal contact, and inhalation) posed a carcinogenic risk to children, whereas the dermal exposure pathway posed a carcinogenic risk to adults. Health risk assessments based on specific source assignments indicate that when managing soil pollution, the control of fossil fuel combustion and vehicular emissions should be prioritized.

Exogenous Streptomyces spp. enhance the drought resistance of naked oat (Avena nuda) seedlings by augmenting both the osmoregulation mechanisms and antioxidant capacities.

Drought is a major obstacle to the development of naked oat industry. This work investigated mechanisms by which exogenous Streptomyces albidoflavus T4 and Streptomyces rochei D74 improved drought tolerance in naked oat (Avena nuda ) seedlings. Results showed that in the seed germination experiment, germination rate, radicle and hypocotyl length of naked oat seeds treated with the fermentation filtrate of T4 or D74 under PEG induced drought stress increased significantly. In the hydroponic experiment, the shoot and root dry weights of oat seedlings increased significantly when treated with the T4 or D74 fermentation filtrate under the 15% PEG induced drought stress (S15). Simultaneously, the T4 treatment also significantly increased the surface area, volume, the number of tips and the root activity of oat seedlings. Both T4 and D74 treatments elicited significant increases in proline and soluble sugar contents, as well as the catalase and peroxidase activities in oat seedlings. The results of comprehensive drought resistance capacity (CDRC) calculation of oat plants showed that the drought resistance of oat seedlings under the T4 treatment was better than that under the D74 treatment, and the effect was better under higher drought stress (S15). Findings of this study may provide a novel and effective approach for enhancing plant defenses against drought stress.

The Multiple Promoting Effects of Suaeda glauca Root Exudates on the Growth of Alfalfa under NaCl Stress.

Under abiotic stress, plant root exudates can improve plant growth performance. However, studies on the effect of root exudates on the stress resistance of another plant are insufficient. In this study, root exudates (REs) were extracted from Suaeda glauca to explore their effect on alfalfa seedlings under salt stress. The results showed that the plant height and fresh weight of alfalfa significantly increased by 47.72% and 53.39% after 7 days of RE treatment at a 0.4% NaCl concentration. Under 1.2% salt stress, REs reduced the Malondialdehyde content in alfalfa by 30.14% and increased the activity of its antioxidant enzymes (peroxidase and catalase) and the content of its osmotic regulators (soluble sugar and proline) by 60.68%, 52%, 45.67%, and 38.67%, respectively. Soil enzyme activity and the abundance of soil-beneficial bacteria were increased by REs. Spearman analysis showed that urease and neutral phosphatase were related to the richness of beneficial bacteria. Redundancy analysis confirmed that urease affected the composition of the soil bacterial community. The partial least squares structural equation model (PLS-SEM) revealed that REs had a direct positive effect on alfalfa growth under salt stress by regulating the plant's injury and antioxidant systems, and the soil bacterial community had an indirect positive effect on alfalfa growth through soil enzyme activity.

Higher Seed Rates Enlarge Effects of Wide-Belt Sowing on Canopy Radiation Capture, Distribution, and Use Efficiency in Winter Wheat.

The optimized winter wheat sowing method comprising wide-belt sowing (WBS) can improve the ears number and biomass to increase the grain yield, compared with conventional narrow-drill sowing (NDS). The seed rate and the interaction between the sowing method and seed rate also affect yield formation. However, the effects of the sowing method and seed rate, as well as their interaction on biomass production, particularly the interception of solar radiation (ISR) and radiation use efficiency (RUE), are unclear. A field experiment was conducted for two seasons in southern Shanxi province, China, using a split-plot design with sowing method as the main plot (WBS and NDS) and seed rate as the sub-plot (100-700 m-2). Our results showed that while WBS had a significant and positive effect, increasing the yield by 4.7-15.4%, the mechanism differed between seed rates. Yield increase by WBS was mainly attributed to the increase in total biomass resulting from both the promoted pre- and post-anthesis biomass production, except that only the increase in post-anthesis biomass mattered at the lowest seed rate (100 m-2). The higher biomass was attributed to the increased ISR before anthesis. After anthesis, the increased ISR contributed mainly to the increased biomass at low seed rates (100 and 200 m-2). In contrast, the increased RUE, resulting from the enhanced radiation distribution within canopy and LAI, contributed to the higher post-anthesis biomass at medium and high seed rates (400 to 700 m-2). The greatest increases in total biomass, pre-anthesis ISR, and post-anthesis RUE by WBS were all achieved at 500 seed m-2, thereby obtaining the highest yield. In summary, WBS enhanced grain yield by increasing ISR before anthesis and improving RUE after anthesis, and adopting relatively higher seed rates (400-500 m-2) was necessary for maximizing the positive effect of WBS, and thus the higher wheat yield.

Probabilistic human health risk assessment of PCDD/Fs near municipal solid-waste incinerator using Monte Carlo analysis coupled with triangular fuzzy numbers.

PCDD/Fs are dioxins produced by waste incineration and pose risks to human health. We aimed to detail the health risks of airborne and soil PCDD/Fs near a municipal solid-waste incinerator (MSWI) for the surrounding population and develop a new model that improves upon existing methods. Thus, we conducted field sampling and then investigated a MSWI in the Pearl River Delta (2016-2018). Our results showed that the carcinogenic and non-carcinogenic risk values of PCDD/Fs exposed to residents in nearby areas were acceptable, with hazard index (HI) values lower than 1.0 and a total carcinogenic risk lower than 1.0E-6. Notably, the results raised concerns regarding higher non-carcinogenic risks in children than in adults. Comparative analysis of the frequency accumulation diagram, accumulated probability risk, and the absolute value of error (δ) between the 95% confidence interval (CI) and the 90% CI of the Monte Carlo stochastic simulation-triangular fuzzy number (MCSS-TFN) and the MCSS model, respectively, demonstrated that the MCSS-TFN exhibited less uncertainty than the MCSS model, regardless of the health risk value of PCDD/Fs in ambient air or in soil. This observation underscores the superiority of the MCSS-TFN model over other models in assessing the health risks associated with PCDD/Fs in situations with limited data. Our new method overcomes the limited dataset size and high uncertainty in assessing the health risks of dioxin substances, providing a more comprehensive understanding of their associated health risks than MCSS models.

Artificial Tactile Sensing Neuron with Tactile Sensing Ability Based on a Chitosan Memristor.

Owing to the highly parallel network structure of the biological neural network and its triggered processing mode, tactile sensory neurons can realize the perception of external signals and the functions of perception, memory, and data processing by adjusting the synaptic weight. In this paper, a piezoresistive pressure sensor is combined with a memristor to design an artificial tactile sensory neuron. The polyurethane sponge sensor has excellent sensitivity and can convert physical stimuli into electrical signals, and the chitosan-based memristor has stable bipolar resistive switching characteristics, allowing further information to be memorized and processed. The neuron can respond to tactile stimuli of different degrees, durations, and frequencies; realize potentiation/depression modulation, paired-pulse facilitation, and spike-timing-dependent plasticity; exhibit spike-rate-dependent plasticity; and store and erase tactile information through memistor state switching, which has great application potential in biological sensing systems.

Novel annual nitrogen management strategy improves crop yield and reduces greenhouse gas emissions in wheat-maize rotation systems under limited irrigation.

Excessive irrigation and nitrogen application have long seriously undermined agricultural sustainability in the North China Plain (NCP), leading to declining groundwater tables and intensified greenhouse gas (GHG) emissions. Developing low-input management practices that meet the growing food demand while reducing environmental costs is urgently needed. Here, we developed a novel nitrogen management strategy for a typical winter wheat-summer maize rotation system in the NCP under limited irrigation (wheat sowing irrigation only (W0) or sowing and jointing irrigation (W1)) and low nitrogen input (360 kg N ha-1, about 70 % of traditional annual nitrogen input). Novel nitrogen management strategy promoted efficient nitrogen fertilizer uptake and utilization by both crops via optimization of nitrogen fertilizer allocation between the two crops, i.e., increasing nitrogen inputs to wheat (from 180 to 240 kg N ha-1) while reducing nitrogen inputs to maize (from 180 to 120 kg N ha-1). Three-year field study demonstrated that integrated management practices combining novel nitrogen management strategy with limited irrigation increased annual yields and PFPN by 1.9-5.7 %, and reduced TGE by 55-68 kg CO2-eq ha-1 and GHGI by 2.2-10.3 %, without any additional cost. Our results provide agricultural operators and policymakers with practical and easy-to-scalable integrated management strategy, and offer key initiative to promote grain production in the NCP towards agriculture sustainable intensification with high productivity and efficiency, water conservation and emission reduction.

Genome-wide identification, phylogeny and expression analysis of the R2R3-MYB gene family in quinoa (Chenopodium quinoa) under abiotic stress.

The MYB transcription factor (TF) are among the largest gene families of plants being responsible for several biological processes. The R2R3-MYB gene family are integral player regulating plant primary and secondary metabolism, growth and development, and responses to hormones and stresses. The phylogenetic analysis combined with gene structure analysis and motif determination resulted in division of R2R3-MYB gene family into 27 subgroups. Evidence generated from synteny analyses indicated that CqR2R3-MYBs gene family is featured by tandem and segmental duplication events. On the basis of RNA-Seq data, the expression patterns of different tissues under salt treatment were investigated resulting CqR2R3-MYB genes high expression both in roots and stem of quinoa (Chenopodium quinoa ) plants. More than half of CqR2R3-MYB genes showed expression under salt stress. Based on this result, CqR2R3-MYB s may regulate quinoa plant growth development and resistance to abiotic stresses. These findings provided comprehensive insights on role of CqR2R3-MYBs gene family members in quinoa and candidate MYB gene family members can be further studies on their role for abiotic stress tolerance in crop plants.

[Application of the follower arm endoscope holder in type i tympanoplasty].

Objective:To investigate the surgical outcomes and safety of the follower arm endoscope holder in assisting type Ⅰ tympanoplasty. Methods:The clinical data of 16 patients who underwent type Ⅰ tympanoplasty at the Department of Otorhinolaryngology, Peking Union Medical College Hospital, from November 2022 to September 2023 were retrospectively analyzed, among which 8 cases were operated by traditional otoscopy and 8 cases were operated by supported endoscopy.The surgical procedure was analyzed and the completion of supported endoscopic operation was observed, while the duration of the operation, the time consumed by the main steps, the frequency of wiping the lenses, the perioperative complications, and the improvement of the postoperative hearing were recorded and statistically analyzed. Results:Supporting endoscopic technology achieved real-time suction of bleeding, simultaneous traction and separation of tissues, precise removal of calcified spots on the inner side of the eardrum, trimming of the external auditory canal flap, stable separation of the handle of the malleus and the eardrum, and tensioned repositioning of the skin-cartilage flap. The average duration of surgery, time for external auditory canal flap preparation, and time for repositioning the skin-cartilage flap were reduced in the supporting endoscopic surgery group compared to the control group. The average lens wiping frequency was significantly lower in the supporting endoscopic surgery group compared to the control group. There was no statistically significant difference in postoperative hearing improvement between the two groups, and no infections or the need for secondary surgery due to eardrum re-perforation occurred postoperatively. Conclusion:Supported endoscopy technology realizes the need for endoscopic two-handed operation and convenient switching between one and two hands, accomplishes many operations that cannot be done by traditional endoscopic surgery, solves the problems of previous intraoperative one-handed operation and image instability, shortens the average operation time compared with traditional otoscopic surgery, and decreases the frequency of intraoperative wiping of the lens significantly compared with traditional otoscopic surgery, which is potentially worthwhile in terms of shortening the learning curve.

Utilizing microbial metabolite in catalytic cascade synthesis of conjugated oligomers for In-Situ regulation of biological activity.

Despite the advances of multistep enzymatic cascade reactions, their incorporation with abiotic reactions in living organisms remains challenging in synthetic biology. Herein, we combined microbial metabolic pathways and Pd-catalyzed processes for in-situ generation of bioactive conjugated oligomers. Our biocompatible one-pot coupling reaction utilized the fermentation process of engineered E. coli that converted glucose to styrene, which participated in the Pd-catalyzed Heck reaction for in-situ synthesis of conjugated oligomers. This process serves a great interest in understanding resistance evolution by utilizing the inhibitory activity of the synthesized conjugated oligomers. The approach allows for the in-situ combination of biological metabolism and CC coupling reactions, opening up new possibilities for the biosynthesis of unnatural molecules and enabling the in-situ regulation of the bioactivity of the obtained products.

Can deep fertilization in spring maize fields improve soil properties and their distribution in soil profile?

Deep fertilization strategy has been proven to be an important fertilizer management method for improving fertilizer utilization efficiency and crop yield. However, the relationship between soil chemical and biochemical characteristics and crop productivity under different fertilization depth patterns still needs comprehensive evaluation. Field tests on spring maize were therefore carried out in the Loess Plateau of China for two successive growing seasons from 2019 to 2020. Four distinct fertilization depths of 5 cm, 15 cm, 25 cm, and 35 cm were used to systematically investigate the effects of fertilization depth on soil physicochemical parameters, enzyme activity, and biochemical properties. The findings demonstrated that although adjusting fertilization depths (D15, D25) did not significantly affect the soil organic carbon content, they did significantly improve the soil chemical and biochemical characteristics in the root zone (10-30 cm), with D25 having a greater influence than D15. Compared with D5, the total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), Olsen-P, dissolved organic carbon, and nitrogen (DOC and DON) in the root zone of D25 significantly increased by 12.02%, 7.83%, 22.21%, 9.56%, 22.29%, and 26.26%, respectively. Similarly, the urease, invertase, phosphatase, and catalase in the root zone of D25 significantly increased by 9.56%, 13.20%, 11.52%, and 18.05%, while microbial biomass carbon, nitrogen, and phosphorus (MBC, MBN, and MBP) significantly increased by 18.91%, 32.01% and 26.50%, respectively, compared to D5. By optimizing the depth of fertilization, the distribution ratio of Ca2-P and Ca8-P in the inorganic phosphorus components of the root zone can also be increased. Therefore, optimizing fertilization depth helps to improve soil chemical and biochemical characteristics and increase crop yield. The results of this study will deepen our understanding of how fertilization depth influence soil properties and crop responses.