Dihydroartemisinin (DHA) inhibits myofibroblast differentiation through inducing ferroptosis mediated by ferritinophagy.

Idiopathic pulmonary fibrosis (IPF) is caused by persistent micro-injuries and aberrant repair processes. Myofibroblast differentiation in lung is a key event for abnormal repair. Dihydroartemisinin(DHA), a well-known anti-malarial drug, have been shown to alleviate pulmonary fibrosis, but its mechanism is not clear. Ferroptosis is involved in the pathgenesis of many diseases, including IPF. Ferritinophagy is a form of cellular autophagy which regulates intracellular iron homeostasis. The function of DHA on myofibroblasts differentiation of pulmonary and whether related with ferroptosis and ferritinophagy are unknown now. Using human fetal lung fibroblast 1(HFL1) cell line and the qRT-PCR, immunofluorescent and Western blotting techniques, we found that after TGF-ß1 treatment, the levels of ɑ-SMA expression and ROS increased; the mRNA and protein levels of FTH1 and NCOA4, the content of Fe2+ and 4-HNE increased significantly at 6h, then gradually reduced with time. After DHA treatment, FHL1 cells appeared ferroptosis; the levels of α-SMA mRNA and protein reduced and the levels of ROS and 4-HNE increased; the Fe2+ levels decreased sharply at 6h, then increased with time, and were higher than normal since 24h; the mRNA and protein levels of FTH1 and NCOA4 decreased, exhibited a downward trend. These results show that Fe2+, ROS and lipid peroxidation are involved in and ferritinophagy is inhibited during fibroblast-to-myofibroblast differentiation; The depletion of Fe2+ at early stage induced by DHA treatment triggers the ferritinophagy in HFL1 cells, leading to degradation of FTH1 and NCOA4 and following increase of Fe2+ levels. DHA may inhibit the fibroblast-to-myofibroblast differentiation through inducing ferroptosis mediated by ferritinophagy.

Optimized strategy to improve the outcomes of acute type A aortic dissection with malperfusion syndrome.

BACKGROUND: The mortality of acute type A aortic dissection (ATAAD) with malperfusion syndrome (MPS) is high. However, the management strategy remains controversial. We aimed to evaluate the strategy for MPS at our institution. METHODS: Among 724 patients with ATAAD, 167 patients with MPS were treated with immediate central repair (first stage) or an optimized strategy (second stage). In the second stage, the optimized strategy used was based on 6-hour threshold from symptom onset. For MPS with symptom onset within 6 hours, immediate central repair was performed, followed by endovascular reperfusion if malperfusion persisted. With symptom onset beyond 6 hours, individualized delayed central repair was performed. We compared outcomes between the first and second stages. RESULTS: The in-hospital mortality of ATAAD was significantly decreased when the optimized strategy was used (4.3% in the second stage vs 12.5% in the first stage; P < .01). In the second stage, the in-hospital mortality for MPS was decreased (10.2% vs 33.9%; P < .01). Moreover, the in-hospital mortality for MPS with symptom onset within 6 hours and beyond 6 hours decreased from 24% to 7.5% and from 41.2% to 11.8%, respectively. The operative mortality of MPS in the second stage was comparable to that in patients without MPS (4.0% vs 2.4%; P > .05). CONCLUSIONS: The optimized strategy significantly improved the outcomes of MPS. The 6-hour threshold from symptom onset could be very useful in determining the timing of central repair. For patients with MPS symptom onset within 6 hours, immediate central repair is reasonable; for those with symptom onset beyond 6 hours, individualized delayed central repair should be considered.

Effects of Blood Hemoadsorption Therapy with HA-380 in Total Arch Replacement for Acute Type A Aortic Dissection: A Retrospective Observational Study.

INTRODUCTION: This study aimed to evaluate whether the addition of a hemoadsorption (HA) cartridge, HA-380, in the cardiopulmonary bypass (CPB) circuit in acute type A aortic dissection (ATAAD) surgery reduced inflammatory cytokine levels and decreased postoperative complications. METHODS: A retrospective observational cohort study was conducted between March 1, 2021, and February 28, 2022. Patients with ATAAD undergoing emergent total arch replacement surgery were divided into the control (CON) and HA groups on the basis of the addition of the HA-380 cartridge in the CPB circuit. RESULTS: Overall, 121 patients met the eligibility criteria; 2 patients in each group who died within the first postoperative week were excluded. Further, 57 and 60 patients in the CON and HA groups, respectively, were included in the pooled analysis. The major perioperative data, baseline values of interleukin-6 (IL-6) and C-reactive protein, and therapeutic interventions were similar in the two groups (all, p > 0.05). The serum IL-6 levels increased more rapidly in the CON group than those in the HA group postoperatively (205.73 ± 174.72 vs. 146.13 ± 64.15 pg/mL, p = 0.020). The HA group had a lower incidence of postoperative acute kidney injury (AKI) and severe acute respiratory distress syndrome than the CON group (25.4 vs. 44.6%, p = 0.032 and 18.3 vs. 35.1%, p = 0.040, respectively). Logistic regression analyses showed that HA may be a protective factor against postoperative AKI. The incidence of bleeding, delirium, and stroke as well as the lengths of intensive care unit and hospital stay in both groups were similar (all, p > 0.05). CONCLUSIONS: The use of HA-380 in the CPB circuit may attenuate inflammatory response and reduce major complications following ATAAD surgery. HA may be associated with lower rate of postoperative AKI.

[Clinical application of a self-developed mouth opener with a tongue base retractor in the operation of deep part of tongue base].

Objective:To test the application effect of a self-developed mouth opener with a tongue base retractor in the operation of the deep part of tongue base. Methods:The tongue base surgical field was exposed by using a self-developed mouth opener with a tongue base retractor in 8 patients who underwent deep tongue base operation via oral approach, the difficulty of operation, the effect of exposure of operation field, the tear of mucous membrane of the pharynx arch and the risk of tongue paralysis were observed. Results:The self-made mouth opener can expose the deep operative field of the tongue root by using the self-provided tongue root retractor during the operation, and the operation is conducted under the guidance of angle endoscope. The operative field of 8 patients was well exposed during the whole operation, there was no pharyngeal mucosa tearing and postoperative tongue paralysis. Conclusion:The self-made mouth opener has the advantages of simple operation, good exposure effect and less complications, but it needs rigid bending instruments in some operations.

Dark matter from axion strings with adaptive mesh refinement.

Axions are hypothetical particles that may explain the observed dark matter density and the non-observation of a neutron electric dipole moment. An increasing number of axion laboratory searches are underway worldwide, but these efforts are made difficult by the fact that the axion mass is largely unconstrained. If the axion is generated after inflation there is a unique mass that gives rise to the observed dark matter abundance; due to nonlinearities and topological defects known as strings, computing this mass accurately has been a challenge for four decades. Recent works, making use of large static lattice simulations, have led to largely disparate predictions for the axion mass, spanning the range from 25 microelectronvolts to over 500 microelectronvolts. In this work we show that adaptive mesh refinement simulations are better suited for axion cosmology than the previously-used static lattice simulations because only the string cores require high spatial resolution. Using dedicated adaptive mesh refinement simulations we obtain an over three order of magnitude leap in dynamic range and provide evidence that axion strings radiate their energy with a scale-invariant spectrum, to within ~5% precision, leading to a mass prediction in the range (40,180) microelectronvolts.

Study on the correlation between urinary retinol-binding protein and nonalcoholic fatty liver disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) affects human health worldwide. Our objective was to explore the correlation between urinary retinol-binding protein (URBP) and NAFLD. METHODS: This cross-sectional study included 445 NAFLD patients and 911 healthy controls. The URBP level and other parameters were measured. RESULTS: The URBP level (expressed by the RBP/creatinine ratio) was higher in the NAFLD patients compared with the non-NAFLD patients. The urinary RBP/creatinine ratio was an independent risk factor for NAFLD after univariate and multivariate regression analysis, with the or values of 2.271 (1.795-2.872, P < 0.001) and 2.338 (1.775-3.080, P < 0.001), respectively. The prevalence of the urinary RBP/creatinine ratio (groups 1, 2, 3, 4) was 20.0%, 17.3%, 27.3%, and 35.4%, respectively (P < 0.001), and the prevalence of NAFLD in the high urinary RBP/creatinine ratio group was significantly higher than that in the low urinary RBP/creatinine ratio group. CONCLUSIONS: Our results revealed that the urinary RBP/creatinine ratio was an independent risk factor for NAFLD.

S100A1 is a sensitive and specific cardiac biomarker for early diagnosis and prognostic assessment of acute myocardial infarction measured by chemiluminescent immunoassay.

BACKGROUND: A member of the S100 family of Ca2+-binding proteins, S100A1 is highly expressed in cardiac muscle tissue. Although this protein is considered an indicator of acute myocardial infarction (AMI), high-throughput and sensitive detection methods are still urgently needed. We constructed a rapid and sensitive method for detecting S100A1 and to investigate the clinical utility of S100A1 as a biomarker for the early diagnosis of AMI and subsequent prognostic assessments. We developed an automated chemiluminescent immunoassay to detect S100A1. We then analyzed the performance of the newly developed assay including evaluation of the analytical sensitivity, analytical selectivity, linear range, accuracy and repeatability. METHODS: We recruited 87 patients with AMI or angina pectoris to explore the value of this marker for the early diagnosis and prognostic assessment. RESULTS: The chemiluminescent-immune-based S100A1 assay had functional analytical sensitivity with a detection limit of 0.13 ng/ml, and a wide linear range of 0.13-31.66 ng/ml. It also exhibited good repeatability with intra-assay and inter-assay findings of <5% and <15%, respectively. Plasma S100A1 was found to have a higher diagnostic sensitivity than conventional cardiac biomarkers (creatine kinase-MB and cardiac troponin T). The survival analysis showed that a higher concentration of plasma S100A1 (>1.02 ng/ml) was notably associated with the poor prognosis of AMI patients after first PCI. CONCLUSIONS: Measurement of circulating S100A1 concentrations with our newly developed chemiluminescent-immune-based assay shows potential for use in the clinic. This assay could enable early identification and prognostic assessment of AMI.

Lipid Peroxidation, GSH Depletion, and SLC7A11 Inhibition Are Common Causes of EMT and Ferroptosis in A549 Cells, but Different in Specific Mechanisms.

Epithelial-mesenchymal transition (EMT) induced by transforming growth factor-ß1 (TGF-ß1) is thought to be involved in the pathogenesis of pulmonary fibrosis. Emerging evidence suggested that there are some common causes between ferroptosis and pulmonary fibrosis. The interaction of EMT and ferroptosis and its mechanism were investigated by detecting the expression levels of α-smooth muscle actin (α-SMA), E-cadherin, solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4) and measuring the contents of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH). The cellular morphology and ultrastructure of mitochondria were studied by microscope and transmission electron microscope (TEM), respectively. The results showed that ferroptosis in A549 cells was induced by Erastin, which decreased the expression levels of E-cadherin (E-Ca), α-SMA, and SLC7A11, accompanied with ROS and MDA increase, as well as GSH decrease. TGF-ß1 promoted ultrastructure variation of mitochondria similar to ferroptosis and mesenchymal changes in morphology during EMT of A549 cells, accompanied with reduced GSH content and expression of SLC7A11, as well as ROS and MDA increase. Ferrostatin-1 (Fer-1) recovered ferroptosis induced by Erastin, but had no effect on the morphological change caused by TGF-ß1. Furthermore, Fer-1 reduced ROS and MDA production, and increased SLC7A11 expression in the early subsequently increased GSH. However, the effects of Fer-1 on above indicators were different in time. The expression of GPX4 had no significant change during EMT induced by TGF-ß1 and ferroptosis induced by Erastin in A549 cells. It is indicating that Erastin promoted the de-epithelialization of lung epithelial cells, but inhibited the process of myofibroblast differentiation; Fer-1 could partially inhibit EMT induced by TGF-ß1, but reverse ferroptosis induced by Erastin. TGF-ß1 could delay the ferroptosis, but could not prevent it. Lipid peroxidation, GSH depletion, and SLC7A11 inhibition are common causes of EMT and ferroptosis in A549 cells, but different in specific mechanisms. The exact effects of GPX4 involved in EMT and ferroptosis in A549 cells need further study.

Pooled Genomic Screens Identify Anti-apoptotic Genes as Targetable Mediators of Chemotherapy Resistance in Ovarian Cancer.

High-grade serous ovarian cancer (HGSOC) is often sensitive to initial treatment with platinum and taxane combination chemotherapy, but most patients relapse with chemotherapy-resistant disease. To systematically identify genes modulating chemotherapy response, we performed pooled functional genomic screens in HGSOC cell lines treated with cisplatin, paclitaxel, or cisplatin plus paclitaxel. Genes in the intrinsic pathway of apoptosis were among the top candidate resistance genes in both gain-of-function and loss-of-function screens. In an open reading frame overexpression screen, followed by a mini-pool secondary screen, anti-apoptotic genes including BCL2L1 (BCL-XL) and BCL2L2 (BCL-W) were associated with chemotherapy resistance. In a CRISPR-Cas9 knockout screen, loss of BCL2L1 decreased cell survival whereas loss of proapoptotic genes promoted resistance. To dissect the role of individual anti-apoptotic proteins in HGSOC chemotherapy response, we evaluated overexpression or inhibition of BCL-2, BCL-XL, BCL-W, and MCL1 in HGSOC cell lines. Overexpression of anti-apoptotic proteins decreased apoptosis and modestly increased cell viability upon cisplatin or paclitaxel treatment. Conversely, specific inhibitors of BCL-XL, MCL1, or BCL-XL/BCL-2, but not BCL-2 alone, enhanced cell death when combined with cisplatin or paclitaxel. Anti-apoptotic protein inhibitors also sensitized HGSOC cells to the poly (ADP-ribose) polymerase inhibitor olaparib. These unbiased screens highlight anti-apoptotic proteins as mediators of chemotherapy resistance in HGSOC, and support inhibition of BCL-XL and MCL1, alone or combined with chemotherapy or targeted agents, in treatment of primary and recurrent HGSOC. IMPLICATIONS: Anti-apoptotic proteins modulate drug resistance in ovarian cancer, and inhibitors of BCL-XL or MCL1 promote cell death in combination with chemotherapy.

Study on the Correlation Between Urinary Transferrin and Nonalcoholic Fatty Liver Disease.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) can cause renal injury, and urinary transferrin (UTRF) is extremely sensitive to renal injury. We aimed to investigate the correlation between UTRF and NAFLD and to observe the distribution of NAFLD at different levels of UTRF. METHODS: A total of 711 subjects fulfilled the diagnostic criteria of NAFLD and 1,396 healthy control participants were enrolled in this study. UTRF levels and other clinical and laboratory parameters were measured. RESULTS: The UTRF level was higher in NAFLD than in non-NAFLD patients. Unit and multiple regression analysis showed that UTRF was an independent risk factor for NAFLD, with OR values of 1.474 (1.328 - 1.635, p < 0.001) and 1.435 (1.267 - 1.625, p < 0.001), respectively. The prevalence of UTRF (groups 1, 2, 3, 4) was 25.61%, 26.56%, 38.14%, and 44.59%, respectively (p < 0.001), and the prevalence of NAFLD in the high UTRF group was significantly higher than in the low UTRF group. CONCLUSIONS: UTRF is an independent risk factor for NAFLD.

Short interfering RNA directed against the GOLPH3 gene enhances the effect of chemotherapy against oral squamous cell carcinoma by regulating Caspase3, Bcl2 and cytochrome-c expression.

Growing evidence reported that Golgi phosphoprotein 3 (GOLPH3) was involved in the progression of several human cancers. To determine whether knockout of GOLPH3 enhances the effect of Chemotherapy against cell growth of oral squamous cell carcinoma in vitro. OSCC cells were transfected with Golph3 plasmid, Golph3-RNAi and the relative control plasmids. Transfected Tca-8113 cells treated with cis-Dichlorodiamineplatinum (DDP; 0, 0.05, 0.25, 1.25, 6.25 and 31.25 ug/ml) or Paclitaxe (0, 2, 10, 50, 250 and 1250 nM) or Adriamycin (0, 0.25, 0.5, 1, 2 and 4 ug/ml) for 24 h, respectively, was determined using MTT assay. Apoptosis-related protein expression Cytochrome-C, Caspase3 and Bcl-2 was analyzed by RT-PCR and western blots. Result of MTT showed that Golph3-RNAi transfected Tca-8113 cells enhanced the effect of chemotherapy, and the effect was strengthened with the increasing concentration of drugs, and the Golph3 plasmid transfected Tca-8113 cells showed the opposite effect. RT-PCR and western blots assays revealed that expression of cytochrome-C and caspase3 were up-regulated, while Bcl-2 expression was down-regulated in Golph3-RNAi transfected Tca-8113 cells. Taken together, this study demonstrated that GOLPH3 had potent pro-tumor growth and decreased the effect of Chemotherapy, and its mechanism is primarily via cell anti-apoptosis, down-regulating the expression of cytochrome-C and caspase3, up-regulating Bcl-2 expression.

Evaluating TBK1 as a therapeutic target in cancers with activated IRF3.

UNLABELLED: TBK1 (TANK-binding kinase 1) is a noncanonical IκB protein kinase that phosphorylates and activates downstream targets such as IRF3 and c-Rel and, mediates NF-κB activation in cancer. Previous reports demonstrated synthetic lethality of TBK1 with mutant KRAS in non-small cell lung cancer (NSCLC); thus, TBK1 could be a novel target for treatment of KRAS-mutant NSCLC. Here, the effect of TBK1 on proliferation in a panel of cancer cells by both genetic and pharmacologic approaches was evaluated. In KRAS-mutant cancer cells, reduction of TBK1 activity by knockdown or treatment with TBK1 inhibitors did not correlate with reduced proliferation in a two-dimensional viability assay. Verification of target engagement via reduced phosphorylation of S386 of IRF3 (pIRF3(S386)) was difficult to assess in NSCLC cells due to low protein expression. However, several cell lines were identified with high pIRF3(S386) levels after screening a large panel of cell lines, many of which also harbor KRAS mutations. Specifically, a large subset of KRAS-mutant pancreatic cancer cell lines was uncovered with high constitutive pIRF3(S386) levels, which correlated with high levels of phosphorylated S172 of TBK1 (pTBK1(S172)). Finally, TBK1 inhibitors dose-dependently inhibited pIRF3(S386) in these cell lines, but this did not correlate with inhibition of cell growth. Taken together, these data demonstrate that the regulation of pathways important for cell proliferation in some NSCLC, pancreatic, and colorectal cell lines is not solely dependent on TBK1 activity. IMPLICATIONS: TBK1 has therapeutic potential under certain contexts and phosphorylation of its downstream target IRF3 is a biomarker of TBK1 activity.

HLA-G1 and HLA-G5 isoforms have an additive effect on NK cytolysis.

The immunotolerant HLA-G could generate seven isoforms including HLA-G1--G7. The suppressive function of either HLA-G1 or HLA-G5 isoform to NK cell cytolysis has been well established. Whether HLA-G1 and HLA-G5 isoform have an additive effect on the cytolysis of NK cells remain to be explored. In this study, effects of expression of HLA-G1 and HLA-G5 isoforms and their combination on NK cytolysis was investigated. NK cell cytolysis was analyzed by detecting the NK cell surface CD107a expression. In this study, data showed that the inhibition capacity is dependent on the level of both HLA-G1 and HLA-G5 expression, but the HLA-G5 isoform has a more potent inhibition effect on the NK cytolysis (p<0.01). Furthermore, HLA-G1 and HLA-G5 have an additive effect on the suppression of NK cell cytolysis. Our study provided further understanding for the roles of HLA-G1 and HLA-G5 isoform expression in target cells immune escaping from NK cells.

[Experimental study on the reconstruction of mandibular defects with sinboneHT bone replacement in rabbits].

OBJECTIVE: After sinboneHT bone replacement (SBR) was implanted in animals, to evaluate the biocompatibility of SBR and compounded in autogenetic bone in the proportion of one to one in order to prepare for the clinical applications in the future. METHODS: Bone defects of 10 mm x l0 mm x 2 mm was made at the mandibular of rabbits, then SBR with different granule diameter and autogenetic bone was compounded in the proportion of being applied in the left defects, while autogenetic bone was implanted in the right defects and nothing was used in the right reformed defects. Animals were sacrificed at 2, 4 and 8 weeks respectively. The biologic capacity was evaluated with anatomy, X-rays studies and histology. RESULTS: SBR has better biocompatibility, which can effectively accelerate the reconstruction of bone defects and help the new bone by being compounded with autogenetic bone. It provides the appropriate scaffold or template which would allow cellular infiltration, attachment and multiplication. CONCLUSION: SBR is a kind of bone substitute material with good biocompatibility. SBR compounded with self-bone has a better regeneration function.

[Effects of hypotonic solution on the proliferation, alkaline phosphatase activity and [Ca2+]i concentration of osteoblast-like cells].

OBJECTIVE: To investigate the effects of static-stretch from the hypotonic solution on the proliferation, alkaline phosphatase activity and [Ca2+]i in the osteoblast-like cells. METHODS: Mechanical loading was introduced by swelling in the hypotonic solution. In vitro cultured MG63 were incubated under continuous swelling of 277, 240 and 163mOsm for 2h, 4h, 8h, 12h, 24h and 48h. The cell proliferation was detected by MTT assay. ALPase and [Ca2+]i were determined by modified enzyme dynamic method and OCPC respectively. RESULTS: The cell proliferation, ALP activity and [Ca2+]i increased slowly under continuous static-stretch of 277 and 240mOsm. The cell proliferation was inhibited under 163mOsm, with a sharp increase of [Ca2+]i at 8h (11.383 +/- 0.111) and an increase of ALPase activity (0.326 +/- 0.002). CONCLUSION: The static-stretch induced from the hypotonic solution has an impact on the proliferation, differentiation, ALPase and Ca2+-ATPase of the MG63. The [Ca2+]i is correlated with the ALPase.

In vitro evaluation of the fracture resistance of anterior endodontically treated teeth restored with glass fiber and zircon posts.

STATEMENT OF PROBLEM: The published information is equivocal regarding the fracture resistance of endodontically treated teeth restored with fiber posts. Additionally, little is known about the biomechanical performance of glass fiber and zircon posts. PURPOSE: This in vitro study investigated the fracture resistance of anterior endodontically treated teeth prepared with a 2-mm ferrule, restored with glass fiber and zircon posts and composite resin cores or cast posts and cores. MATERIAL AND METHODS: Twelve matched pairs of teeth were obtained from 4 cadavers, and all were endodontically treated and prepared with a standardized 2-mm ferrule. According to a random number table, the 2 teeth from each matched pair were randomly divided into 2 groups. The test group consisted of 12 specimens restored with a glass fiber and zircon post (Fibio) and composite resin (Durafil) core. Twelve matching specimens restored with a nickel-chromium (NiCr) cast post and core served as the control. Specimens in both groups were cemented with resin cement (Panavia F). After cementation of cast NiCr complete crowns with zinc polycarboxylate cement (ShangChi), the specimens were loaded with an incremental static force at an angle of 135 degrees to the long axis of the root until failure occurred. A paired sample t test was used to compare the fracture resistance (N) of teeth restored with the 2 post-and-core systems (alpha=.05). RESULTS: The mean failure load of paired differences between the 2 groups was -261.3+/-237.3 N. The test group exhibited significantly lower failure loads than the control group (P=.004). All specimens displayed root fractures, most of which were oblique, with cracks initiating from the palatal cervical margin and propagating in a labial-apical direction. CONCLUSION: Within the limitations of this study, the teeth restored with glass fiber and zircon posts demonstrated significantly lower failure loads than those with cast NiCr post and cores. All specimens failed via root fractures.

Models for GRBs and diverse transients.

The observational diversity of gamma-ray bursts (GRBs) has been increasing, and the natural inclination is a proliferation of models. We explore the possibility that at least part of this diversity is a consequence of a single basic model for the central engine operating in a massive star of variable mass, differential rotation rate and mass loss rate. Whatever that central engine may be-and here the collapsar is used as a reference point-it must be capable of generating both a narrowly collimated, highly relativistic jet to make the GRB and a wide angle, sub-relativistic outflow responsible for exploding the star and making the supernova bright. To some extent, the two components may vary independently; therefore, it is possible to produce a variety of jet energies and supernova luminosities. We explore, in particular, the production of low-energy bursts and find a lower limit of approximately 10(48)ergs(-1) to the power required for a jet to escape a massive star before that star either explodes or is accreted. Lower energy bursts and 'suffocated' bursts may be particularly prevalent when the metallicity is high, i.e. in the modern universe at low red shift.