Search

BackgroundThe axillary lymph node positive (ypN+) rate in patients with clinically node-negative (cN0) breast cancer who have achieved breast pathologic complete response (bpCR) after neoadjuvant systemic therapy (NST) is extremely low, and this population has the potential to be exempt from sentinel lymph node biopsy (SLNB). However, an overview of the ypN+ rate in this population for different breast cancer subtypes is lacking.ObjectiveTo provide the pooled ypN+ rate in cN0 patients who achieved bpCR after NST in different breast cancer subtypes defined by hormone receptor (HR) status and human epidermal growth factor receptor 2 (HER2) status.MethodsA systematic literature search was conducted in Embase and PubMed on July 20, 2022. Two authors independently selected studies that met the inclusion criteria and extracted all data. The pooled ypN+ rates for each subtype were calculated by a random-effects model using the Stata 16.0 metaprop command.ResultsThe pooled analysis of 9609 cN0 patients who achieved bpCR showed that the ypN+ rate was lowest for the HR+/HER2+ (0%) subtype, followed by HR+/HER2- (5.1%), HR-/HER2+ (0.6%), and HR-/HER2- (0.3%). Additionally, 6571 cT1-T2N0 patients who achieved bpCR had a pooled ypN+ rate of 0.6%, and the ypN+ rates for different subtypes were as follows: HR+/HER2+ (1.7%), HR+/HER2- (2.7%), HR-/HER2+ (0.1%), and HR-/HER2- (0.8%).ConclusionOur results suggested that cN0 patients who achieve bpCR may be exempt from axillary surgery in the HR+/HER2-, HR+/HER2+, and HR-/HER2- subtypes because of the extremely low probability of residual axillary lymph node disease. However, the safety of omitting axillary surgery needs to be further confirmed by prospective studies.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/#recordDetails, identifier CRD42022351739.

The incidence of toxic diffuse goiter (Graves' disease) is higher in adolescents and preschool-aged children, with an upward trend. The incidence at 6-13 years of age is approximately 11.0%, and the incidences in men and women are 7.8% and 14.3%, respectively.To explore the clinical effect of methimazole combined with selenium in the treatment of toxic diffuse goiter (Graves' disease) in children and its effect on serum anti-thyroglobulin antibody (TRAb) and anti-thyroid peroxidase antibody (TPOAb).A total of 103 children with Graves' disease treated in our hospital from January 2018 to June 2021 were divided into a traditional group and a combined group (15-20 mg methimazole orally given to children) and a combined group (50 µg selenium added on the basis of traditional treatment) according to different treatment methods to explore the therapeutic effects of the two methods and to observe the changes in thyroid volume and serum TRAb, TPOAb, free thyroxine (FT4) and inflammatory factor levels before and after treatment. The time taken for FT4 to return to normal was compared between the two groups.Treatment was significantly more effective in the combined group than in the traditional group (Methimazole combined with selenium can effectively treat Graves' disease in children, reduce the expression of TRAb, TPOAb, FT4 and inflammatory factors, and improve the curative effect. Thus, the combined treatment warrants further clinical research.

Objective To explore the risk factors associated with esophagojejunal anastomotic leakage (EJAL) after curative total gastrectomy combined with D2 lymph node dissection for gastric cancer. Methods We reviewed the data for 390 consecutive patients undergoing Roux-en-Y esophagojejunostomy reconstruction after total gastrectomy. Multivariate analysis was performed using a logistic regression model to identify the independent risk factors for EJAL. Results Of the 390 patients enrolled in this study, EJAL occurred in 10 patients (2.6%), and one patient (1/10) with EJAL died. Univariate analysis identified age, alcohol consumption, pulmonary insufficiency, and intraoperative blood loss as risk factors for EJAL. Of these four risk factors, age and alcohol consumption were retained as independent risk factors by multivariate analysis. Conclusion Surgeons should be very careful regarding anastomotic leakage after esophagojejunal anastomosis, perioperatively, especially in patients with advanced age and a history of alcohol consumption. Pulmonary insufficiency and intraoperative blood loss, although not identified as independent risk factors, should also be considered.

Additional file 1: Table S1. Clinicopathological characteristics of colorectal cancer patients with isolated initial lung metastasis.

Additional file 2: Table S2. Sequencing information of the five primary tumors, five metastatic tumors and five non-cancerous comparators.

Objects The aim of this trial was to evaluate the effect of short-term high-dose atorvastatin therapy on levels of high-sensitivity C-reactive protein (hs-CRP), malonaldehyde (MDA), endothelin-1(ET-1), matrix metalloproteinases (MMPs), and left ventricular (LV) remodeling in patients with first time attack of acute anterior myocardial infarction (AAMI) .Methods A hundred and three patients with first time attack of AAMI who underwent successful primary percutaneous coronary intervention were randomized to receive atorvastatin 40 mg once daily for 1 week followed by 20 mg once daily (intensive treatment group, IT group, n=49), or atorvastatin 20 mg once daily (standard treatment group, ST group, n=54). Plasma levels of hs-CRP, MDA, ET-1, MMP-2 and MMP-9 were measured on admission, at 1 week, 2 weeks and 6 months follow up and compared between the IT group and ST group. Echocardiography was performed on admission, at 2 week, and 1 year follow up. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) were measured at each echocardiographic examination and compared between the IT group and ST group.Results Plasma levels of hs-CRP (F=7.718, P=0.009), ET-1 (F=7.882, P=0.006), MMP-9 (F=4.834, P=0.028) and pro-BNP (F=4.603, P=0.032) were significantly lower at 1 week after initial onset of AAMI in the IT group compared with the ST group. The changes of LVEDV, LVESV, and LVEF at the 1 year follow-up from the admission did not differ between the IT group and the ST group (t=0.722, P=0.444; t=1.228, P=0.221; t=1.354, P=0.187, repectively).Conclusions Short-term high-dose atorvastatin treatment for AAMI was associated with lower hs-CRP, ET-1 and MMP-9 levels compared to the standard dose treatment. However, this beneficial effect is not likely to related to the left ventricular remodeling.

Figure S4. Sensitivity of T47D cells to tamoxifen is regulated by p53 and survivin (A) Knockdown of p53 increases survivin level in T47D cells. T47D cells were transfected with siRNA specifically targeting p53 as described in “Methods”. The protein levels of p53, NgBR, survivin and β-actin were determined using western blot analysis. (B) Quantitative analysis of proteins presented in Additional file 5: Figure S5A were carried out using ImageJ and were normalized to β-actin. Data are presented as fold changes in the si-p53 group compared to the NS group. (C) Knockdown of p53 decreases apoptosis of T47D cells induced by 4-OHT (1 μM). (D) Percentages of apoptotic cells in Additional file 5: Figure S5C are shown in the bar graph. (E) Survivin knockdown increases apoptosis of T47D-TamR cells induced by 4-OHT (5 μM). (F) Percentages of apoptotic cells in Additional file 5: Figure S5E are shown in the bar graph. (PDF 292 kb)

Figure S3. NgBR decreases the resistance of T47D-TamR to tamoxifen. (A) NgBR knockdown increases apoptosis of T47D-TamR cells induced by 4-OHT (5 μM). The apoptotic cells were detected by Annexin V-PI staining. The total number of cells in the Q2 and Q4 quadrant was regarded as apoptotic cells. (B) Percentages of apoptotic cells are shown in the bar graph. (C) NgBR knockdown decreases the viability of T47D-TamR cells. Cell viability was determined using trypan blue staining of T47D-TamR cells treated with 5 μM 4-OHT for 48 h. The viable cell number of the NS group is referred to as 100%. (D) NgBR knockdown decreases the clonogenenicity of T47D-TamR cells. The clonogenic survival assay was used for measuring clonogenicity of T47D-TamR cells treated with 4-OHT (5 μM). (E) Quantification of colony number in colony formation assays presented in Additional file 3: Figure S3D. The data are from three separate repeated experiments and are presented as the mean ± SD (*p

Figure S5. NgBR knockdown attenuated EGF-stimulated signaling and ERα phosphorylation in T47D-TamR cells. (A) T47D-TamR cells were transfected with siNgBR and treated with EGF (100 ng/mL) for 5 min. Downstream signaling of the EGF pathway was determined using western blot assay. (B) Quantitative analysis of phosphorylated proteins presented in Additional file 10: Figure S6A were carried out using ImageJ and were normalized to total proteins. The data are from three separate repeated experiments and are presented as the mean ± SD (*p

Figure S2. NgBR is highly expressed in the tamoxifen-resistant T47D-TamR cells. (A) NgBR level was increased in T47D-TamR cells. Protein levels of Nogo-B, ERα, p53 and survivin in T47D and T47D-TamR cells were determined using western blot analysis. (B) Quantitative analysis of proteins presented in Additional file 2: Figure S2A was carried out using ImageJ and normalized to β-actin. Data are presented as fold changes of T47D-TamR compared to the T47D cells. The data are from three separate repeated experiments and are presented as the mean ± SD (*p

Table S1. Sequences of primers. (DOCX 18 kb)

Figure S6. Relapse-free survival (RFS) in patients with ERα-positive breast cancer (n = 343). NgBR (NUS1) mRNA expression data were retrieved from the GSE6532 database. Kaplan–Meier analysis revealed significantly reduced RFS (p

Water quality deterioration of reservoir served as municipal water source has been a potential threat to public health. Crowned as one of the largest reservoirs and water resource, Miyun reservoir has been paid attention to water quality protection. For the purpose of effective reservoir protection and management, comprehensive understanding of water quality spatiotemporal pattern is demanded. In this study, three dimensional (3-D) dynamic Environmental Fluid Dynamics Code (EFDC) model was used to simulate hydrodynamic and algal processes for Miyun reservoir. Main challenge was to demonstrate the water quality pattern and implying impacts on variations. Model structure and functionality were briefly described. Field data and estimated loads were used as nutrient forces. Calibration and summary statistics were presented. Results showed that spatiotemporal pattern of water temperature, dissolved oxygen, chlorophyll-a, total phosphorous, nitrate and ammonia were consistent with in situ measurements. Several important impacts on the water quality variations in Miyun reservoir were discussed. It indicated that the existence of the patterns were highly related to the geomorphogical and hydrological characteristics as well as nutrient inputs. Temporal tendency was also linked to the seasonal climate. It proved that EFDC model was feasible for hydro-environmental simulation in Miyun reservoir, providing managers an efficient tool for strong supports on water quality management and water source protection.

Raman spectroscopy has been widely used as an important clinical tool for real-time in vivo cancer diagnosis. Raman information can be obtained from whole organisms and tissues, at the cellular level and at the biomolecular level. The aim of this paper is to review the newest developments of Raman spectroscopy in the field of breast cancer diagnosis and treatment. Raman spectroscopy can distinguish malignant tissues from noncancerous/normal tissues and can assess tumor margins or sentinel lymph nodes during an operation. At the cellular level, Raman spectra can be used to monitor the intracellular processes occurring in blood circulation. At the biomolecular level, surface-enhanced Raman spectroscopy techniques may help detect the biomarker on the tumor surface as well as evaluate the efficacy of anticancer drugs. Furthermore, Raman images reveal an inhomogeneous distribution of different compounds, especially proteins, lipids, microcalcifications, and their metabolic products, in cancerous breast tissues. Information about these compounds may further our understanding of the mechanisms of breast cancer.

Objective To explore the gap junction function and pacing function transformed myocardial cells, rat bone marrow mesenchymal stem cells (BMSCs) transfected by hyperpolarization activated cyclic nucleotide-gated cation channel 4 (HCN4) gene were co-cultured with neonatal rat cardiomyocytes (CM). Methods After being labelled with DAPI, neonatal rat CM were co-cultured with BMSCs, HCN4+ BMSCs or HCN4– BMSCs for 4 days, respectively. The spontaneous beating frequency of cells in each group was then detected, and the anatomical location of two types of cells was observed by fluorescence microscopy. Western blotting was used to detect the expression of connexin 43 (Cx43), and the intercellular gap junction was observed by transmission electron microscopy. Results The spontaneous beating rate of ventricular myocardium was significantly higher after being cultured. The anatomical location of BMSCs was found to be adjacent to CM under fluorescence microscope. Western blotting showed that Cx43 expression was significantly higher in HCN4+ MSC co-cultured with CM group than in HCN4– BMSCs cultured with CM group. Transmission electron microscopy revealed that HCN4+ BMSCs formed to be interlaced with adjacent CM. Conclusion The rat BMSCs transfected by HCN4 gene may establish an effective electro-mechanical connection with cardiomyocytes, the spontaneous pacing function is close to that of CM, and the result provides an experimental basis for promoting biological pacemaker therapy. DOI: 10.11855/j.issn.0577-7402.2013.12.02

To the analysis and further development of straight-racket-hit skill of table tennis, visual simulation is established to help finding its character through comparing with straight racket backhand skill. To overcome such flaws as unable to exert enough force and difficult to determine a strike point, an optimal angle to achieve the skill is got through analyzing force of different angle of wrist and forearm. Through analyzing the visual simulation of mechanical arm, a systematic theory is established to orient the training of straight-racket-hit skill.

The photocurrent and spectral response characteristics of gallium arsenide (GaAs) are obtained by a multi-information measurement system, and the evolution of the photocurrent versus the Cs:O flux ratio is investigated. The experimental results show that the photocurrent increases approximately exponentially after the first exposure to Cs until a maximum sensitivity is reached, the detailed evolution process and the ultimate photocurrent are different for different samples. These differences are analysed, and according to the process of coadsorption of Cs and oxygen on GaAs, an equation is presented to explain the increase of photocurrent.

Porous/hollow polymer microparticles were prepared by suspension polymerization from a resol, water-soluble phenolic resin in a multiple emulsion system oil-in-water-in-oil(O/W/O). The porous/hollow structures of phenolic resin microparticle were characterized by optical microscopy (OM) and scanning electron microscopy (SEM). It is shown that the porous/hollow structure is related to a dispersion and curing process of the resol resin. It was indicated that it is low-cost and simple to prepare porous/hollow phenolic resin micr-particles from resol in an O/W/O system. Copyright © 2007 John Wiley & Sons, Ltd.

The filling process of plastic precise gear is simulated by CAE software and the factors that influence injection molding accuracy in single cavity mold are discussed in this paper. With the assistant of visualization technology, the mechanism of filling unbalance which influences efficient injection molding was especially studied. The model of filling unbalance was supposed that was verified experimentally by visualization technique. It is clarified that the mechanism of filling unbalance results from dissymmetrical temperature distribution on the cross-section of runner, which is strongly influenced by the shear heat and the cooling process in the runner. At the same time, a new method was proposed for improving the filling imbalance by applying appropriate injection molding process without any changes in runner shape of multi-cavity mold.

To determine the association of procalcitonin (PCT) with trauma severity and post traumatic sepsis in children.The blood samples of 30 children with acute trauma in a Pediatric unit were collected for four consecutive days. The levels of PCT, IL-6, CRP and WBC were measured. The pediatric trauma score (PTS), length of stay in hospital, incidence of sepsis and clinical outcomes of the children were recorded. The value of PCT for predicting prognosis of children with trauma was compared with other inflammatory markers.Plasma PCT levels increased significantly in the patients in our study. Sepsis occurred in 23.33% of the patients. The patients with sepsis had higher levels of PCT than those with and without systemic inflammatory response syndrome (SIRS) and the healthy controls (P0.05). The peak level of PCT emerged on day 2 after trauma. The plasma PCT levels were positively correlated with trauma severity. The level of PCT on day 2 was an independent predictor for post-trauma sepsis and SIRS.Plasma PCT levels increase markedly in post trauma children. Plasma PCT of day 2 after trauma is an independent predictor of post-traumatic sepsis and SIRS complications. There is a significant correlation between the severity of injury and plasma PCT.

Molecular orientation and stacking mode are commonly considered to have vital influence on the optoelectronic performances of organic semiconductor devices via changing the dynamics of charge carriers transferring among the molecules. Highly ordered and homogeneous stacking would allow a fast band transfer mechanism in the phase domain. Therefore the controls of the molecular orientation and the stacking behavior are of great significance for optimizing the device natures. In this work, the modification and control of iron phthalocyanine (FePc) molecular orientation on Si(111) are accomplished with the aid of high steady magnetic field at room temperature. The FePc films are grown in situ by organic molecular beam deposition on the Si(111) substrates under a high magnetic field strength of 8.5 T. The Si(111) substrates are preserved at room temperature and are kept perpendicular to the magnetic field. The influences of magnetic field on the molecular orientations and the morphologies of FePc thin films are investigated by X-ray diffraction, angle dependent near edge X-ray absorption fine structure (NEXAFS), Raman spectroscopy and atomic force microscopy (AFM). In the presence of the external magnetic field, the deposited FePc films each show a higher crystallinity and slightly closer packing in (002) plane than those without magnetic field. The AFM images verifies more ordered and uniform morphologies of the FePc films grown in the magnetic field. NEXAFS and Raman results both reveale a standing-up configuration of FePc molecules on the Si(111) substrate surface. The average tilting angle of the molecules changes from 63.6 to 67.1 when 8.5 T magnetic field is employed. The results demonstrate that the external high magnetic field distinctly enhances the orientation order of FePc molecules on Si(111) surface due to the magnetic-magnetic interactions between the magnetic field and the molecular magnetic moment. This work also demonstrates that external magnetic field is an efficient means to regulate the orientation and stacking behavior of magnetic molecules, which may open a new way to optimize the performances of the organic semiconductor devices.

The paper presents the principle and calculation process of the principal component analysis which is a useful method of water quality assessment. Eight indicators include dissolved oxygen, permanganate index, BOD, ammonia nitrogen, copper, zinc, volatile phenol, oil in 20 monitoring sections of Ningbo urban river were analyzed by using principal component analysis. Three factors with 86.67% of accumulated contribution rates were extracted from the original data, which include organic matter factor, heavy metal matter factor, ammonia nitrogen and volatile phenol factor. The results show that 50% water sections cani¯t reach the standards, most of them located in Yinzhou River, YinRiver and Fenghua River. The results consist with the actual situation.

This letter outlines the design and manufacture of a miniaturized bandpass filter realized by low-temperature cofired ceramic (LTCC) technology for bluetooth applications. The bandpass filter with a central frequency of 2450 MHz and a 100 MHz passband is designed as a three-dimensional (3-D) structure based on lumped components. Experimental measurements were compared with modeling. The insertion losses in the passband (100 MHz) were less than 1.2 dB and the attenuation was more than 20 dB in the stop band. The area occupied by the filter is 1.6times0.8times0.6 mm3.

This paper presents a new compact 90deg hybrid coupler using multi-layer technology. In order to reduce an intrinsic circuit area of the hybrid coupler, a compact meandered line configuration and a new multi-layer structure design have been adopted. The configuration and structural dimensions of the multi-layer structure were designed and investigated through detailed 3-D electro-magnetic simulations. The measured insertion loss is less than 0.4 dB, and the phase imbalance is less than 3 degree with the frequency range from 380 MHz to 520 MHz. The overall dimension is as small as 16.5 mm times 12.2 mm times 1.66 mm.

To investigate whether the PJ interval in the patients with pre-excitation syndrome can be shortened by pathway conduction, and to explore the clinical implications of the prolonged PJ interval.143 patients with single pathway, who experienced successful radiofrequency (RF) ablation, were divided into two groups: Group A (n = 132) with normal atrioventricular and ventricular conduction (sub-divided into 10 subsets further according to the location of the pathway) and Group B (n = 11) with first degree atrioventricular block or with bundle branch block. The ECG images with and without pathway conduction were analyzed.(1) The PJ interval in the patients with right posterior pathway or with right septal pathway was shortened significantly after the RF [(226 +/- 18) ms vs (236 +/- 19) ms and (221 +/- 18) ms vs (238 +/- 31) ms respectively, both P0.05 ]; (2) The PJ interval in Group B was shortened to different extents. The PJ interval values in 4 patients with first degree atrioventricular block were shortened, but still beyond normal extent. The PJ interval values in 4 patients with bundle branch block were shortened to normal extent.If the pre-excitation syndrome patients have normal atrioventricular conduction the PJ interval is normal or the PJ interval may be shortened. If the patients have prolonged atrioventricular conduction, the PJ interval may be shortened by the pathway prograde conduction. PJ interval prolongation indicates atrioventricular conduction delay or ventricular conduction block, but bundle branch block cannot be excluded when the PJ interval is normal.

A LTCC band-pass filter with dual transmission zeros for Bluetoothtrade application was presented. With the classic network synthesis method, a lumped LC filter was educed and then transformed to physical prototype with LTCC process. This prototype was refined with DOE method, and was implemented in Zhejiang Zhengyuan Electric Co. Ltd. The measured insertion loss is less than 1.8 dB at 2400 MHz, and two transmission zeros are obtained at 1.7 and 7.1 GHz, respectively. They result in 40-45 dB for lower stop band suppression and 45-50 dB for higher stop band reduction. The experimental data agree very well with the 3-D simulation.

The present status of research on negative electron affinity (NEA) GaN vacuum surface electron source is discussed with considering the latest research conclusions from our country and foreign country. Some valuable results about GaN vacuum electron source have been obtained including the theory of photoemission, the surface depuration method, the activation technique for GaN photocathode, the measurement of spectral response, the characteristics of material etc. The mechanism of photoemission for NEA GaN vacuum electron source is studied preliminarily. The depuration method of obtaining the atom cleanness surface is given. The GaN material is effectively activated with Cs or Cs/O. The spectral response of GaN vacuum electron source material is measured. The material characteristics affecting the quantum efficiency of the electron source are analyzed. The next investigation is also mentioned.

Aiming at determining the quantum efficiency of fully activated negative electron affinity(NEA) GaN photocathodes, we have investigated the spectral response of NEA GaN photocathodes by using a dedicated ultraviolet spectral response measurement instrument. The quantum efficiency curve of reflection-mode NEA GaN photocathode has been obtained in the band region from 230nm to 400nm. The experimental results show that the quantum efficiency of reflection-mode NEA GaN photocathode reaches up to 37.4% at 230 nm, and at 365 nm, which is the threshold of GaN photocathode, the quantum efficiency remains 3.75%. A sharp cutoff characteristic with over two orders of magnitude degradation from 230 nm to 400 nm has been observed. Based on the former research results, the factors influencing quantum efficiency were also comprehensively analyzed in the paper.

The photocurrent curves during either Cs or Cs/O activation of GaN photocathode were tested by using dedicated experimental system for activation and evaluation of negative electron affinity （NEA） photocathode. Aiming at explaining the formation of NEA property of GaN photocathode and according to the rule of photocurrent change during activation period and the surface model of a fully activated photocathode，the activation mechanism for NEA GaN photocathode was studied. The experiment results show that：the obvious NEA property is be induced in GaN photocathode mainly due to the activation by Cs. The increase extent of photocurrent is not large after introducing O during Cs/O activation process for GaN photocathode. The NEA property formation reasons of GaN photocathode after being activated successfully can be well explained using the double dipole layer model ［GaN（Mg）：Cs］：O—Cs.

The photocurrent curves of reflection-mode GaAs photocathodes as a function of time, when were illuminated by white light with an intensity of 0, 33 and 100lx, respectively, were measured using a multi-information measurement system. The calculated lifetimes of cathodes are 320, 160 and 75min, respectively, showing that the stability of cathodes degraded with the increase of light intensity. The lifetime of cathode, illuminated by white light with an intensity of 100lx, while no photocurrent was being drawn during the illumination, was 100min. Through comparison, we found that the influence of illumination on cathodes stability is greater than that of photocurrent. The quantum-yield curves of cathodes as a functions of time, when illuminated by white light with an intensity of 33lx, were measured also. The measured results show that the shape of the yield curves changes with increasing illumination time due to the faster quantum-yield degradation rate of low energy photons. Based on the revised quantum-efficiency equations for the reflection-mode cathodes, the variation of yield curves are analyzed to be due to the intervalley diffusion of photoelectrons and the evolution of the surface potential barrier profile of the photocathodes during degradation process.

Figure S1. MCF-7-TamR and T47D-TamR cells are resistant to 4-OHT. The 4-OHT resistant phenotype was confirmed using the CCK8 cell viability assay. (A) Cell viability was analyzed in MCF-7 and MCF-7-TamR cells treated with 1 μM 4OHT for different time periods (0, 1 day, 3 days and 5 days). (B) Cell viability was analyzed in T47D and T47D-TamR cells treated with 1 μM 4OHT for different time periods (0, 1 day, 3 days and 5 days). The OD value of untreated cells is referred to as 100%. The results show the average percentage of OD value as compared to untreated cells. The data are from in three separate repeated experiments, and are presented as the mean ± SD (*p

Figure S1. MCF-7-TamR and T47D-TamR cells are resistant to 4-OHT. The 4-OHT resistant phenotype was confirmed using the CCK8 cell viability assay. (A) Cell viability was analyzed in MCF-7 and MCF-7-TamR cells treated with 1 μM 4OHT for different time periods (0, 1 day, 3 days and 5 days). (B) Cell viability was analyzed in T47D and T47D-TamR cells treated with 1 μM 4OHT for different time periods (0, 1 day, 3 days and 5 days). The OD value of untreated cells is referred to as 100%. The results show the average percentage of OD value as compared to untreated cells. The data are from in three separate repeated experiments, and are presented as the mean ± SD (*p