Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective To optimize the design of the existing water conductivity control system for pharmaceutical water equipment of full membrane process so as to solve its problems in precision and long cycle time due to water source,ambient temperature and intermittent working mode.Methods The optimized water conductivity control system was composed of an alkali metering pump,a conductivity sensor and a programmable logic controller(PLC),which used a fuzzy proportional-integral-derivative(PID)controller to regulate the water conductivity of pharmaceutical water equipment of full membrane process,and the particle swarm optimization(PSO)algorithm to optimize the parameters of the fuzzy PID controller.A simulation model was established with MATLAB software to verify the performance of the optimized control system.Results Simulation results showed the optimized control system had reductions in overshoot(by 19％)and adjustment time(by 29％)when compared with the fuzzy PID control system,and enhanced control efficiency effectively.Conclusion The optimized control system optimized by the PSO algorithm improves the quality of produced water,and can meet the demands for rapid and safe production of pharmaceutical water by pharmaceutical water equipment of full membrane process in different conditions.[Chinese Medical Equipment Journal,2025,46(6):14-19]

Objective:To construct and validate a three-level early warning model of moderate to severe ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology.Methods:A case-control study was conducted. Totally 10 181 infertility patients who underwent in vitro fertilization treatment in Reproductive Medicine Center, Women and Children's Medical Center Affiliated to Guangzhou Medical University from April 2013 to April 2023 were retrospectively analyzed and divided into modeling group (8 145 cases) and validation group (2 036 cases) by random number table method. The clinical data of the two groups were analyzed, and the risk factors affecting the occurrence of moderate and severe OHSS after oocytes retrieval were screened by multi-factor logistic regression analysis. The early warning model was established and the column diagram was drawn at three nodes which were before ovarian stimulation, before trigger and 3 d after oocyte retrieval. The receiver operating characteristic (ROC) curve and calibration curve were used to verify the models. Results:The antral follicle count (AFC, OR=1.045, 95% CI: 1.020-1.071, P<0.001), anti-Müllerian hormone (AMH)>3.36 μg/L ( OR=7.135, 95% CI: 2.084-24.432, P=0.002) and number of cycles ( OR=0.149, 95% CI: 0.022-1.026, P=0.049) were included in the pre-stimulation prediction model. AFC ( OR=1.046, 95% CI: 1.018-1.074, P=0.001), AMH>3.36 μg/L ( OR=5.780, 95% CI: 1.661-20.116, P=0.006), gonadotropin releasing hormone-agonist protocols ( OR=3.895, 95% CI=1.913-7.931, P<0.001), estrogen peak≥18 350 pmol/L ( OR=2.258, 95% CI: 1.092-4.666, P=0.028), the number of follicles with a diameter of ≥10 mm>20 ( OR=2.377, 95% CI: 1.092-5.172, P=0.029) were included in the pre-trigger prediction model. AMH>3.36 μg/L ( OR=8.374, 95% CI: 2.417-29.019, P=0.001), estrogen peak≥18 350 pmol/L ( OR=3.947, 95% CI: 1.533-10.167, P=0.004), total number of oocytes retrived ( OR=1.042, 95% CI: 0.996-1.090, P=0.025), abdominal distension ( OR=60.181, 95% CI: 22.515-160.854, P<0.001), fresh transplantation ( OR=21.766, 95% CI: 7.119-66.544, P<0.001), human chorionic gonadotropin trigger ( OR=17.752, 95% CI: 3.993-78.924, P<0.001) were included in the prediction model of 3 d after oocyte retrieval. The areas under ROC curves of the three models were 0.830 (95% CI: 0.782-0.878), 0.859 (95% CI: 0.812-0.906) and 0.948 (95% CI: 0.919-0.977), respectively. The areas under ROC curves of the validation groups of the three models were 0.922 (95% CI: 0.880-0.965), 0.936 (95% CI: 0.886-0.986), and 0.971 (95% CI: 0.938-0.999), respectively. The calibration curve indicated that the early-warning evaluation model has good stability. Conclusion:The three-level early warning model of moderate and severe OHSS has good differentiation, reliable predictability and clinical practicability, which is conducive to the dynamic and continuous assessment of the risk of moderate and severe OHSS, adjustment of treatment plan at any time, and timely adoption of effective preventive measures.

Objective To explore the effects of different glucose concentrations on the synthesis and secretion of bone collagen in osteoblasts and the impact of diabetes on bone quality in mice.Methods(1)Primary osteoblasts were extracted from the skulls of neonatal mice via collagenase digestion and cultured in four groups under different glucose concentrations:normal glucose(5.5 mmol/L),moderate glucose(11.5 mmol/L),moderate-high glucose(16.5 mmol/L),and high glucose(25 mmol/L).EdU staining was performed to evaluate cell proliferation,while the Transwell assay was used to assess cell migration.Immunofluorescence and Western blotting were performed to detect and quantitatively analyze the content of type Ⅰ collagen(Col-1).Alizarin red S(ARS)staining and alkaline phosphatase(ALP)staining were applied to assess the effects of different glucose concentrations on osteogenic differentiation.(2)Six-week-old male C57BL/6 mice were randomly divided into control group and model group(5 in each group).The model group was fed a high-fat diet for 4 weeks followed by streptozotocin(STZ)injection to establish a diabetic mouse model.The osteogenic differentiation capacity of primary osteoblasts from both groups was assessed.(3)Micro-computed tomography(Micro-CT)was employed to analyze femoral bone mineral density(BMD),bone volume/tissue volume(BV/TV),trabecular number(Tb.N),and trabecular separation(Tb.Sp).Three-point bending test was conducted to evaluate mechanical parameters including maximum load,Young's modulus,fracture energy,and stiffness.RT-qPCR was employed to assess the expression of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox).Masson staining and Mallory staining were used to evaluate Col-1 content in trabecular bone.Results(1)EdU and Transwell assay results demonstrated that with the gradual increase in glucose concentration,the proliferation and migration abilities of osteoblasts were significantly decreased(P<0.001),and the protein expression levels of Col-1 and lysyl oxidase(LOX)were significantly reduced(P<0.01 or P<0.001).ARS and ALP staining revealed that calcium salt deposition and ALP activity in osteoblasts were significantly decreased with increasing glucose concentration(P<0.05 or P<0.001).(2)Compared with control group,mice in model group exhibited typical"three polies and one weight loss"symptoms(polyuria,polydipsia,polyphagia,and weight loss)of diabetes,and ARS and ALP staining showed a significant reduction in osteoblasts(P<0.001).(3)Micro-CT and three-point bending test results indicated that,compared with control group,mice in model group showed microarchitectural deterioration of bone,decreased Tb.N,increased Tb.Sp,and significantly reduced maximum load,Young's modulus,fracture energy,and stiffness(P<0.05).RT-qPCR results showed that the relative mRNA expression levels of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox)were significantly decreased in model group compared with control group(P<0.01 or P<0.001).Masson and Mallory staining indicated a significant reduction in collagen content in model group compared with control group(P<0.01).Conclusions High-glucose environment inhibits osteoblast proliferation,differentiation,and migration.Diabetic mice exhibit reduced bone quality and increased bone fragility,potentially mediated by decreased lysyl oxidase and collagen levels.

Objective To explore the relative positioning of the superior orbital fissure and internal carotid artery through CT three-dimensional reconstruction,and to provide anatomical references for safe dissection during surgeries involving the orbital apex from a radiological perspective.Methods Totally 64 cases(128 sides)of head and neck CT angiography were analyzed and Mimics 21.0 software was employed for three-dimensional reconstruction.Measurements were taken on the three-dimensional models,including the distance from the inner boundary of the superior orbital fissure to the anterior convexity,proximaldural ring,and distaldural ring of the internal carotid artery.Distances were also measured from the lower boundary of the superior orbital fissure to the anterior convexity,proximaldural ring,and distaldural ring of the internal carotid artery.Additionally,measurements were taken from the upper boundary of the superior orbital fissure to the anterior convexity,proximaldural ring,and distaldural ring of the internal carotid artery.Patient demographic data such as gender,age,and sphenoid sinus aeration were recorded,and anatomical variations were analyzed in correlation with the measured result.Results Distances were measured as follows,d1(6.32±1.98)mm,d2(7.13±2.66)mm,and d3(9.88±2.29)mm from the inner boundary of the superior orbital fissure to the anterior convexity,proximaldural ring,and distaldural ring of the internal carotid artery,respectively.Distances were also measured as d4(11.93±2.17)mm,d5(10.39±2.36)mm,and d6(16.18±2.28)mm from the lower boundary of the superior orbital fissure to the anterior convexity,proximaldural ring,and distaldural ring of the internal carotid artery,respectively.Distances from the upper boundary of the superior orbital fissure to the anterior convexity,proximaldural ring,and distaldural ring of the internal carotid artery were measured as d7(7.91±2.55)mm,d8(9.63±2.99)mm,and d9(10.09±2.72)mm,respectively.The relative distance between the superior orbital fissure and the cavernous segment of the internal carotid artery was significantly greater in males than in females.In patients under 20 years of age,d7-d9 were significantly smaller than in patients over 20 years old,with statistically significant differences.There was a correlation between the type of sphenoid sinus aeration and the main measured parameters d1-d6,while the degree of sphenoid sinus aeration and the presence of the superior orbital fissure were not significantly correlated with the main measured parameters.Conclusion Three-dimensional reconstruction based on CT angiography provides a better assessment of the distance between the superior orbital fissure and internal carotid artery.This method holds clinical reference value for orbital apex surgeries and ensures a safe dissection distance.

Objective To evaluate the value of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)in differentiating histopathological types of brain metastases from non-small cell lung cancer(NSCLC).Methods Sixty-eight patients with brain metastases confirmed by pathology were collected,including 47 lung adenocarcinoma patients divided into a lung adenocarcinoma group and 21 lung squamous cell carcinoma patients into a lung squamous cell carcinoma group.The two groups were compared in terms of the DCE-MRI derived parameters including volume transfer constant(Ktrans),extra vascular extracellular volume fraction(Ve)and plasma volume fraction(Vp);ROC curves were used to assess the diagnostic efficacy of different quantitative parameters for the pathologic types of brain metastases from lung adenocarcinoma group or lung squamous cell carcinoma.SPSS 22.0 software was used for statistical analysis.Results The lung adenocarcinoma group had the values of Ktrans,Ve,Vp and Ve+Vp higher than those of the lung squamous cell carcinoma group,with the differences being statistically significant(all P＜0.05).ROC curve analysis results showed that Ktrans,Vp and Ve had high differential diagnosis values for the pathologic types of brain metastases from lung adenocarcinoma group or lung squamous cell carcinoma,with the AUC being 1.000,0.998 and 0.875,the optimal Youden index being 0.183 min-1,0.039 and 0.270,the sensitivity being 100.00％,100.00％and 80.56％and the specificity being 100.00％,97.06％and 80.88％,respectively.Conclusion The quantitative parameters of DCE-MRI gain advantages in the differential diagnosis of NSCLC brain metastases,and provide references for the diagnosis and treatment of brain metastases of lung cancer.[Chinese Medical Equipment Journal,2025,46(5):54-59]

The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.

Objective:To construct and validate a three-level early warning model of moderate to severe ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology.Methods:A case-control study was conducted. Totally 10 181 infertility patients who underwent in vitro fertilization treatment in Reproductive Medicine Center, Women and Children's Medical Center Affiliated to Guangzhou Medical University from April 2013 to April 2023 were retrospectively analyzed and divided into modeling group (8 145 cases) and validation group (2 036 cases) by random number table method. The clinical data of the two groups were analyzed, and the risk factors affecting the occurrence of moderate and severe OHSS after oocytes retrieval were screened by multi-factor logistic regression analysis. The early warning model was established and the column diagram was drawn at three nodes which were before ovarian stimulation, before trigger and 3 d after oocyte retrieval. The receiver operating characteristic (ROC) curve and calibration curve were used to verify the models. Results:The antral follicle count (AFC, OR=1.045, 95% CI: 1.020-1.071, P<0.001), anti-Müllerian hormone (AMH)>3.36 μg/L ( OR=7.135, 95% CI: 2.084-24.432, P=0.002) and number of cycles ( OR=0.149, 95% CI: 0.022-1.026, P=0.049) were included in the pre-stimulation prediction model. AFC ( OR=1.046, 95% CI: 1.018-1.074, P=0.001), AMH>3.36 μg/L ( OR=5.780, 95% CI: 1.661-20.116, P=0.006), gonadotropin releasing hormone-agonist protocols ( OR=3.895, 95% CI=1.913-7.931, P<0.001), estrogen peak≥18 350 pmol/L ( OR=2.258, 95% CI: 1.092-4.666, P=0.028), the number of follicles with a diameter of ≥10 mm>20 ( OR=2.377, 95% CI: 1.092-5.172, P=0.029) were included in the pre-trigger prediction model. AMH>3.36 μg/L ( OR=8.374, 95% CI: 2.417-29.019, P=0.001), estrogen peak≥18 350 pmol/L ( OR=3.947, 95% CI: 1.533-10.167, P=0.004), total number of oocytes retrived ( OR=1.042, 95% CI: 0.996-1.090, P=0.025), abdominal distension ( OR=60.181, 95% CI: 22.515-160.854, P<0.001), fresh transplantation ( OR=21.766, 95% CI: 7.119-66.544, P<0.001), human chorionic gonadotropin trigger ( OR=17.752, 95% CI: 3.993-78.924, P<0.001) were included in the prediction model of 3 d after oocyte retrieval. The areas under ROC curves of the three models were 0.830 (95% CI: 0.782-0.878), 0.859 (95% CI: 0.812-0.906) and 0.948 (95% CI: 0.919-0.977), respectively. The areas under ROC curves of the validation groups of the three models were 0.922 (95% CI: 0.880-0.965), 0.936 (95% CI: 0.886-0.986), and 0.971 (95% CI: 0.938-0.999), respectively. The calibration curve indicated that the early-warning evaluation model has good stability. Conclusion:The three-level early warning model of moderate and severe OHSS has good differentiation, reliable predictability and clinical practicability, which is conducive to the dynamic and continuous assessment of the risk of moderate and severe OHSS, adjustment of treatment plan at any time, and timely adoption of effective preventive measures.