To evaluate the features of carotid web (CW) by ultrasonography.

A total of 66 patients with CW were retrospectively enrolled from January 2018 to June 2019 at Xuanwu Hospital, Capital Medical University. All patients were examined by both ultrasonography and CTA, and were divided into either a<50% stenosis group (54 cases) or a ≥50% stenosis group (12 cases). The ultrasonographic characteristics of CW, including the length, thickness, direction (forward or backward to the flow), acute angle between the web and carotid wall, and thrombus between the web and carotid wall were compared between the two groups. The stenosis degrees of carotid artery were compared between patients with and without ischemic stroke.

Forty-two (42/66, 63.6%) patients were diagnosed with CW by initial CDFI examination, of whom 21 (21/66, 31.8%) were diagnosed with ulcerative plaque and 3 (3/66, 4.5%) were diagnosed with carotid dissection at first but confirmed by second examination. There were no differences in the web length, thickness, direction, or thrombus detected between the two groups (P>0.05). The angle between the web and carotid wall in the<50% stenosis group was significantly smaller than that of the ≥50% stenosis group (median angel 39o vs 73o, P=0.002), and the percentage of patients with an angle≤ 60o in the<50% stenosis group was significantly higher than that of the ≥50% stenosis group (74.1% vs 41.7%, P=0.042). The diameter of the residual carotid artery at CW location in the<50% stenosis group was significantly larger and peak systolic velocity was significantly higher in the<50% stenosis group than in the≥50% stenosis group (P<0.001). The stenosis degrees of carotid artery were not statistically different between patients with and without ischemic stroke (P=0.321).

Ultrasonography can be used to evaluate the characteristics of carotid web in 2D and color mode. When the angle between the CW and carotid wall is large, the carotid artery stenosis ≥ 50% is more likely to happen, but carotid artery stenosis is not the main cause of ischemic stroke.

The aim of the present study was to evaluate the efficiency of sling exercise, therapeuticultrasound, therapeuticultrasound and sling exercise in patients to alleviate pain and improve lumbar function with lumbar disc herniation.

Individuals were selected from a list of patients being followed at the department of Rehabilitation in the third hospital of Hebei Medical University. 30 patients who were diagnosed with lumbar disc herniation were collected, the diagnoses were established upon medical history, physical examination, and results of imaging studies. The patients were randomly divided into three groups: therapeuticultrasound group received 14 sessions of ultrasonic therapy to the lumbar region, Sling exercise group received 14 sessions of sling exercise, and therapeuticultrasound and sling exercise group received therapeuticultrasound and sling exercise therapy 14 sessions of therapeuticultrasound to the lumbar region,7 sessions per week, 2 weeks. The VAS and ODI were compared with the assessment of the patients before and at the end of the therapy.

At the end of treatment, three groups VAS scores (F=3.069, P=0.043) and ODI scores (t=12.676, P<0.001) was lower than that at the beginning of treatment (P<0.05), at the end of treatment the VAS scores (F=59.400, P<0.001) and of the ODI scores (t=12.737, P<0.001) of ultrasonic and sling exercise therapy group was lower than the other group, the difference is significantly.

All three groups could reduce pain and improve lumbar function, and the ultrasonic and sling exercise therapy was most effective for lumbar disc herniation treatment in the three groups.

To analyze the treatment of different types of traumatic cerebral infarction in children, and explore its pathogenesis in combination with literature so as to improve the cure rate and reduce disability rate.

The clinical data of 42 cases of traumatic cerebral infarction in children were retrospectively analyzed in The Hospital of 81^st Group Army PLA from January 2015 to December 2019. The diagnosis of traumatic cerebral infarction in children was made by CT scan and MRI scan. According to different conditions, children with traumatic cerebral infarction were classified, and different treatment strategies were selected. Children with lacunar infarction were treated with calcium antagonists and neurotrophic drugs, supplemented by hyperbaric oxygen and exercise rehabilitation. The children of focal cerebral infarction and complex cerebral infarction treated by junior dehydrant and hormone also included the calcium antagonist and nutritional nerve drugs. The therapeutic regimen perhaps adjusted by the evolution of the disease. The children of extensive cerebral infarction underwent emergency cranial decompression, and was treated by reducing intracranial pressure and preventing complications after operation. The treatment results and recovery were observed.

In 42 cases of traumatic cerebral infarction in children, 35 cases (83.3%) were good recovery, 4 cases (9.5%) were moderate disability, 2 cases (4.8%) were severe disability, 1 case (2.4%) died, and no vegetative state. The good recovery rate of lacunar infarction was 100%, that of focal cerebral infarction was 62.5%, that of mixed cerebral infarction was 60%, and that of extensive cerebral infarction was 50%.

It is of great significance to improve the therapeutic effect and prognosis of children with traumatic cerebral infarction to adopt different treatment schemes for different types of cerebral infarction.

To characterize the patients with supratentorial hypertensive intracerebral hemorrhage (ICH) in the Tibetan Plateau over an altitude of 4000 meters.

A total of 68 cases with supratentorial hypertensive ICH were retrospectively included in Ali Regional People’s Hospital from January 2017 to September 2018. The clinical and laboratory data were collected. A simple linear correlation analysis was applied to analyze the correlation between the amount of bleeding and sex, age, nationality, time from onset , systolic blood pressure (SBP), diastolic blood pressure (DBP), hemoglobin (Hb), serum triglyceride (TG), and cholesterol. According to computed tomography (CT) findings, 68 cases were divided into the basal ganglia ICH group (33 cases) and the lobar ICH group (35 cases). The characteristics between two groups were analyzed using t-test or χ² test.

The data of sex, age, nationality, time from onset, SBP, DBP, Hb, TG, and cholesterol of 68 cases on admission did not show any definitive correlation with the hematoma volumes (P＞0.05). The SBP and DBP of patients in the basal ganglia ICH group were significantly higher than that in the lobar ICH group, respectively [(184.9±28.5) mmHg vs (164.6±24.4) mmHg; (113.0±18.1) mmHg vs (103.0±18.4) mmHg] (t=0.499, 0.486; P=0.002, 0.033).

The relevant factors of hematoma volumes in patients with ICH in plateau area were not yet clear. Diastolic and systolic blood pressure of patients in the basal ganglia ICH group was higher than that in those in lobar ICH group.

To compare the efficacy evaluation of electrospun composite biomaterials and a porcine small intestine submucosa mesh for hernia repair.

A randomized, single-blind, controlled multicenter trial was performed in 3 hospitals in Shanghai. Eligible adult patients with primary unilateral reducible groin hernias were randomly assigned (1∶1) to electrospun composite biomaterials (experimental group) or porcine small intestine submucosa (control group) mesh groups. Patients were treated with the tARB technique and assessed at 1,3 and 6 months after the surgery. The primary endpoint was hernia recurrence. The secondary endpoints were postoperative complications including groin pain and operative site infections.

172 patients were assigned to experimental (n=86) and control (n=86) groups. At 6 months follow-up, postoperative complications occurred in 5 patients (5/86, 5.95%) and 2 (2/86, 2.35%) patients in the control and experimental groups, respectively (P>0.05). There was no significant difference in VAS or SVS score between the two groups.

We demonstrate that electrospun composite biomaterial mesh can be used as a ideal choice for inguinal hernia repair. Electrospun composite biomaterial has the characteristics of low recurrence rate, absorbability and long-term comfort.It can be further applied in clinical practice in the future.

Pancreaticoduodenectomy(PD)remains one of the most complicated hepatobiliary operations. The development of minimally invasive surgery for PD has always been an hot spot. Laparoscopic pancreaticoduodenectomy(LPD) has not been widespread carried out due to its difficulty and long learning curve. LPD accounts for 9% of all PD, according to the National Cancer Data base. Compared with laparoscopic surgery, robotic surgery system has significant advantages in the field of minimally invasive PD, including stereotactic amplified vision, filtering hand tremor and simulating the wrist. The article would review the surgical techniques and notes, which could provide clinical reference for other surgeons.

To explore the protective effect of sulforaphane (SFN) on septic myocardial injury (SMI) rats.

Sixty male wistar rats were randomly divided into a sham operation group, an SMI group, and an SFN group, with 20 rats in each group. Rats in the SMI group were prepared by cecum ligation and puncture (CLP), rats in the sham operation group were only exposed to the cecum by laparotomy, and rats in the SFN group were injected with 5 mg/kg SFN infusion 6 hours after CLP. Ten rats were selected from each group and observed for 48 hours after the operation; the mortality of rats at each time point was recorded. The hemodynamics of the remaining rats in each group were monitored by intraventricular catheterization through the right common carotid artery 24 hours after the operation, including heart rate, mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), maximal rate of left ventricular pressure rise during systole (+dp/dtmax), and maximum negative rate of left ventricular pressure decline (-dp/dtmax). The serum levels of cardiac troponin I (cTnI) and lactate dehydrogenase (LDH) and the myocardial tissue levels of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), nitric oxide (NO) and reactive oxygen species (ROS) were measured by the enzyme-linked immunosorbent assay (ELISA). The protein expression levels of Toll-like receptor 4 (TLR4) and nuclear factor E2-related factor 2 (Nrf2) in myocardial tissue were determined by western-blotting.

There was a statistically significant difference in the survival time among the three groups (χ² = 23.720, P < 0.001), but there was no statistically significant difference in the survival time between the SMI group and the SFN group (P = 0.084). The expression levels of heart rate, LVSP, LVEDP, +dp/dtmax, -dp/dtmax, cTnI, LDH, TNF-α, IL-1β, NO, and ROS among the three groups showed statistically significant differences (F = 54.901, 95.190, 94.335, 111.104, 76.477, 1 263.532, 57.782, 1 130.698, 338.950, 155.727, 342.914; all P < 0.001). Compared with the sham operation group, the heart rate, LVSP, +dp/dtmax, and -dp/dtmax in the SMI group and SFN group were significantly decreased, and the above indicators in the SMI group were lowest (all P < 0.05); the levels of LVEDP, cTnI, LDH, TNF-α, IL-1β, NO, and ROS in both the SMI group and the SFN group were significantly increased, and the above indicators in the SMI group were highest (all P < 0.05). Western-blotting showed that there were statistically significant differences in the expression levels of Nrf2 and TLR4 in myocardial tissues among the three groups (F = 26.294, 32.667; both P < 0.001). Compared with the SMI group, the expression of Nrf2 in the SFN group was significantly increased, and the expression of TLR4 was significantly decreased (both P < 0.05).

SFN can alleviate septic myocardial inflammation and oxidative stress in rats and has a certain protective effect on SMI. Its mechanism of action may be related to the inhibition of TLR4 and the enhancement of the Nrf2 signaling pathway.

To evaluate the impact of phosphate supplementation therapy on the in-hospital mortality in septic patients with hypophosphatemia, and to identify the optimal serum phosphorus threshold for sepsis management.

The relevant clinical data of patients with sepsis were collected from the Medical Information Mart for Intensive Care Ⅳ (MIMIC-Ⅳ) database and Electronic Intensive Care Unit-Collaborative Research Database. The logistic regression model was used to assess the effect of phosphate supplementation therapy on in-hospital mortality in septic patients with hypophosphatemia. The blood phosphorus level was divided into six intervals, including significant hypophosphatemia (< 15 mg/L), mild hypophosphatemia (15-25 mg/L), normal low value (> 25-35 mg/L), normal high value (> 35-45 mg/L), mild hyperphosphatemia (> 45-55 mg/L), and significant hyperphosphatemia (> 55 mg/L). The proportion of exposure time of septic patients in each blood phosphorus interval was calculated by the time-weighted method, and the optimal blood phosphorus threshold was determined by the logistic regression model.

A total of 29 729 patients with sepsis were included, 250 856 blood phosphorus test data were analyzed, and 4 849 patients developed hypophosphatemia (serum phosphorus < 27 mg/L). Logistic regression analysis showed that septic patients with hypophosphatemia who received phosphate supplementation were significantly associated with a higher in-hospital mortality rate [odds ratio (OR) = 1.509, 95% confidence interval (CI) (1.203, 1.895), P < 0.001]. In the subgroups excluding patients with acute kidney injury (AKI) and/or refeeding syndrome (RFS), this association remained significant (all P < 0.05). There were 24 051 septic patients who had at least one recorded blood phosphorus test every 24 hours during the ICU period. Logistic regression analysis showed that septic patients with mild hypophosphemia [OR = 0.574, 95%CI (0.473, 0.697), P < 0.001] and those in the normal low value range [OR = 0.411, 95%CI (0.352, 0.480), P < 0.001] had a significantly reduced risk of in-hospital mortality.

Phosphate supplementation therapy cannot improve the prognosis of septic patients with hypophosphatemia. The optimal serum phosphorus level for septic patients is 15-35 mg/L, which is lower than the traditional reference range.

To explore prognostic factors of patients with sepsis complicated with immunocompromised status and to construct a predictive model.

A retrospective analysis was conducted on the clinical data of ICU patients with sepsis in the Affiliated Suzhou Hospital of Nanjing Medical University from April 2023 to February 2025. The general data and laboratory index of patients were analyzed. The statistically significant indicators in the univariate analysis were included in the multivariate logistic regression analysis, and a model of the regression equation was constructed. The model fitting degree was evaluated by the Omnibus test and the Hosmer-Lemeshow test, and the prognosis prediction value of each index was evaluated by drawing receiver operating characteristic (ROC) curves.

In total, 203 sepsis patients were combined with immunocompromised status, including 109 patients (53.7%) in the survival group and 94 patients (46.3%) in the death group. Univariate analysis showed that sequential organ failure assessment (SOFA), lactic acid (Lac), C-reactive protein (CRP), lymphocyte count (LYM), albumin and C-reactive protein/albumin ratio (CAR) were influencing factors of 28-day prognosis in sepsis patients with immune impairment (all P < 0.05). The above indicators were included in the multivariate logistic regression analysis. The research results showed that the SOFA score [odds ratio (OR) = 1.101, 95% confidence interval (CI) (1.004, 1.207), P = 0.041], Lac level [OR = 1.225, 95%CI (1.016, 1.478), P = 0.034] and CAR [OR = 1.183, 95%CI (1.063, 1.317), P = 0.002] were independent risk factors affecting the 28-day prognosis of patients. The logistic regression model was established, and the regression equation was: Logit (P) = 0.096X₁ + 0.203X₂ + 0.168X₃ - 1.854, with X₁, X₂ and X₃ representing the SOFA, Lac and CAR. The Omnibus test and the Hosmer-Lemeshow test suggested that the model was well fitting. The area under the curve of the prediction model was 0.690 [95%CI (0.618, 0.762), P < 0.001], the sensitivity was 60.6%, the specificity was 72.5%, and the Youden index was 0.331.

The SOFA score, Lac and CAR are the influencing factors for the 28-day prognosis of immunocompromised patients with sepsis. The prediction model constructed based on the SOFA score, Lac and CAR can effectively predict the 28-day prognosis of immunocompromised patients with sepsis.

To investigate the protective effect of sivelestat sodium, a neutrophil elastase (NE) inhibitor, on acute lung injury (ALI) after cardiopulmonary bypass (CPB) by regulating alveolar macrophages (AMs) polarization and to analyze its impact on clinical outcomes.

A prospective study was conducted on 65 patients with ALI after CPB admitted to the Department of Critical Care Medicine of the Shaoxing People's Hospital between April 2023 and April 2025. Patients were randomly divided into a Sivel group (n = 32) and a Ctrl group (n = 33) using a single-blind group random number table. The basic information, 30-day mortality, stroke incidence, and the utilization rate of extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) were collected. The changes of bilateral pulmonary exudation after CPB, ventricular arrhythmia, lactate elevation > 48 h, new-onset atrial fibrillation, mechanical ventilation time, ICU stay time, and the oxygenation index, C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), white blood cell (WBC) and neutrophil (Neu) ratio at the time of ICU admission and on the 1st, 3rd and 5th days after surgery were observed. On the 1st day after surgery, bronchoalveolar lavage fluid (BALF) was collected to measure tumor necrosis factor-alpha (TNF-α), IL-10, and high mobility group box 1 (HMGB1) levels. AMs were cultured, and the messenger RNA (mRNA) expression levels of M1 polarization markers [inducible nitric oxide synthase (iNOS), TNF-α, and IL-1β] and M2 polarization marker [arginase-1 (Arg1)] were quantified using real-time fluorescence quantitative PCR. Immunofluorescence was used to assess iNOS and CD206 expression in AMs.

There were no significant differences in the 30-day mortality, ECMO utilization, stroke incidence, or CRRT utilization between the Sivel group and the Ctrl group (all P > 0.05). However, the Sivel group showed significant improvement in reduced bilateral pulmonary exudative changes [28.12% (9/32) vs. 54.55% (18/33), χ² = 5.909, P = 0.015], lower incidence of new-onset atrial fibrillation [6.25% (2/32) vs. 24.24% (8/33), χ² = 4.040, P = 0.044], shorter mechanical ventilation time [(3.7 ± 2.1) d vs. (5.2 ± 2.5) d, χ² = 3.727, P = 0.014], and shorter ICU stay [(75 ± 47) h vs. (97 ± 25) h, χ² = 2.257, P = 0.031] compared with the Ctrl group. In the Sivel group, the oxygenation index improved on the 1st day after surgery, while PCT and CRP levels improved on the 3rd and 5th days as compared with the Ctrl group (all P < 0.05). BALF analysis on the first postoperative day revealed lower TNF-α and HMGB1 levels but higher IL-10 levels in the Sivel group than in the Ctrl group (all P < 0.05). AMs studies showed increased Arg1 mRNA expression and decreased iNOS, TNF-α, and IL-1β mRNA expression in the Sivel group as compared with the Ctrl group (all P < 0.05). Immunofluorescence confirmed increased CD206 positive cells and decreased iNOS positive cells in the Sivel group.

Sivelestat sodium may protect against CPB-induced ALI and improve clinical outcomes by promoting M2 macrophage polarization and reducing inflammation.

To investigate the clinical characteristics, pathogen spectrum, and epidemic patterns of severe pneumonia patients, and to analyze the association between different pathogen spectrum infections and severe pneumonia with respiratory failure.

This study systematically reviewed all hospitalized children diagnosed with severe pneumonia at Changzhou Children's Hospital from December 2020 to March 2024. By extracting medical history, we described the basic characteristics, age distribution, pathogen spectrum, and comorbid respiratory failure of children with severe pneumonia, compared the differences in respiratory failure among children infected with different pathogens, and used multiple logistic regression analysis to explore the impact of different pathogen spectra on respiratory failure in children with severe pneumonia.

During the study period, 2 177 children with severe pneumonia were included. Among them, 319 (14.65%) had respiratory failure. Compared with the period before 2023, the number of children hospitalized with severe pneumonia has increased sharply since 2023, with rises observed across different pathogens and age groups. Notably, the increase was most pronounced for severe pneumonia patients caused by Mycoplasma pneumoniae (MP), which accounted for 51.92% (962/1 853) of all severe pneumonia patients since 2023. Among 319 children with severe pneumonia complicated with respiratory failure, MP infection accounted for 17.55% (56/319), and 49.22% (157/319) were infants aged ≤ 1 year. Multivariate analysis identified age, low birth weight, spring season, bacterial-bacterial co-infection, and bacterial-viral co-infection as risk factors for respiratory failure in children with severe pneumonia (all P < 0.05).

During the 2023-2024 period, the number of severe pneumonia patients caused by various pathogens increased significantly, with MP being the main cause. However, severe pneumonia due to MP infection rarely leads to respiratory failure. Infants under one year old are likely to be a high-risk group for severe pneumonia with respiratory failure. Additionally, bacterial-bacterial and bacterial-viral co-infections may be important risk factors for this complication in children.

In patients with ACTH-independent Cushing's syndrome (primarily including adrenal cortical adenomas and adenocarcinomas) following surgery, glucocorticoid replacement therapy is required due to long-term hypercortisolism-induced suppression of the hypothalamic-pituitary-adrenal (HPA) axis function. This article reviews the three-phase management strategy for this population postoperatively: the acute phase (days 0-14 postoperatively) primarily involves intravenous hydrocortisone, with transition to oral administration based on clinical and biochemical indicators; the tapering phase (2 weeks to 24 months postoperatively) employs a stepwise dose reduction regimen while monitoring symptoms and biochemical parameters; and the long-term follow-up phase (>24 months postoperatively) evaluates HPA axis recovery through ACTH stimulation tests to determine the timing of discontinuation. Additionally, medication adjustments for special populations such as children, pregnant women, and elderly patients are summarized. The aim is to provide practical references for perioperative glucocorticoid management in clinical practice.

Urothelial carcinoma (UC) represents the most common malignant neoplasm of the urinary system. Conventional diagnostic modalities, including radiographic imaging, endoscopic biopsy, and urinary cytology, are limited by radiation exposure, invasive morbidity, and inadequate sensitivity. In recent years, non-invasive urinary genomic assays have rapidly evolved, with DNA methylation, genetic mutations, and transcriptomic signatures emerging as highly promising molecular biomarkers. This systematic review examines the utility of these three classes of genomic biomarkers in UC diagnosis and post-treatment recurrence surveillance, providing a clinical reference framework.

Adhesive capsulitis (AC) is a disease in which the range of motion (ROM) of the shoulder joint is limited due to chronic inflammation and fibrosis of the joint capsule. It is usually manifested as thickening of the glenohumeral ligament or axillary capsule, joint capsule contracture, and reduced joint volume. The axillary capsule is the most relaxed part of the joint capsule, allowing for sliding when the shoulder joint is abducted and rotated. When chronic inflammation and fibrosis of the joint capsule cause contracture and thickening, the abduction, external rotation (ER), and internal rotation (IR) angles of the shoulder joint will also be restricted. For AC patients, the current imaging examination methods mainly include ultrasound and magnetic resonance imaging. Relevant studies have shown that the normal thickness of the axillary sac under ultrasound is approximately 1.3-2.8 mm, and the threshold for diagnosing AC is about 3.2-3.34 mm. The normal axillary sac thickness under magnetic resonance imaging is approximately 2.9 mm, and the threshold for diagnosing AC is about 4.0-5.0 mm. Ultrasound has the advantages of being non-invasive, convenient, and real-time. It can also dynamically observe the morphological changes of the axillary sac during joint movement, making it more suitable for pre-treatment assessment and post-treatment follow-up of AC. Magnetic resonance imaging (MRI) can simultaneously assess lesions in the axillary sac, rotator cuff tendons, and surrounding soft tissues, making it more suitable for preoperative evaluation. However, to date, most scholars have focused mainly on the threshold for diagnosing AC, the therapeutic effect of AC treatment, and the consistency of axillary capsule measurement by ultrasound and MRI. However, few scholars have compared ultrasound-measured axillary capsule thickness with shoulder joint ROM.

To verify the correlation between axillary capsule thickness and physical examination angle, as well as the correlation between the measurement of axillary capsule thickness by ultrasound and magnetic resonance imaging.

In this study, 30 healthy volunteers were included for ultrasound and physical examination, and 36 patients diagnosed with unilateral AC in the outpatient department of our hospital were included for ultrasound, MRI, and physical examination. Personal information, axillary sac thickness, and physical examination angles (including abduction, external rotation, and internal rotation) were collected for correlation analysis and measurement consistency analysis.

Data show that, in healthy shoulder joints, there is no statistically significant difference in parameters such as age, BMI, and axillary sac thickness between healthy volunteers and patients; however, there is a statistically significant difference in internal rotation (P=0.042). The axillary sac on the affected side was significantly negatively correlated with external rotation (r=-0.360, P=0.031) and internal rotation (r=-0.497, P=0.002), while significantly positively correlated with height (r=0.429, P=0.009) and weight (r=0.361, P=0.030). After controlling for the healthy side, the difference in axillary capsule thickness was significantly negatively correlated with the difference in external rotation (r= -0.373, P = 0.025), and the correlation improved. It was significantly negatively correlated with the difference in internal rotation (r = -0.383, P = 0.021), and the correlation was weakened. In addition, this study found that the thickness of the axillary capsule measured by ultrasound (4.39±1.19) mm was significantly lower than that measured by MRI (9.08±2.03) mm, and there was a significant positive correlation between ultrasound and MRI measurements (r=0.676, P<0.001) .

This cross-sectional study fully confirmed a significant negative correlation between axillary cyst thickness and physical examination angles (external and internal rotation). The consistency of axillary cyst measurement by ultrasound and magnetic resonance imaging was moderate, and the thickness measured by magnetic resonance imaging was significantly greater than that measured by ultrasound. Meanwhile, comparing healthy volunteers with those with limited IR revealed that limited IR might be an early warning factor for AC.