Eversion technique versus traditional carotid endarterectomy with patch angioplasty: a systematic review with meta-analyses and trial sequential analysis.

Introduction: The use of an 'eversion' technique is not unequivocally proven to be superior to carotid endarterectomy with patch angioplasty. An up-to-date systematic review is needed for evaluation of benefits and harms of these two techniques. Methods: RCTs comparing eversion technique versus endarterectomy with patch angioplasty in patients with a symptomatic and significant (≥50 %) stenosis of the internal carotid artery were enrolled. Primary outcomes were all-cause mortality rate, health-related quality of life and serious adverse events. Secondary outcomes included 30-day stroke and mortality rate, (a) symptomatic arterial occlusion or restenosis, and adverse events not critical for decision making. Results: Four RCTs were included with 1272 surgical procedures for carotid stenosis; eversion technique n = 643 and carotid endarterectomy with patch closure n = 629. Meta-analysis comparing both techniques showed, with a very low certainty of evidence, that eversion technique might decrease the number of patients with serious adverse events (RR 0.47; 95% CI 0.34 to 0.64; p ≤ 0.01). However, no difference was found on the other outcomes. TSA demonstrated that the required information sizes were far from being reached for these patient-important outcomes. All patient-relevant outcomes were at low certainty of evidence according to GRADE. Conclusions: This systematic review showed no conclusive evidence of any difference between eversion technique and carotid endarterectomy with patch angioplasty in carotid surgery. These conclusions are based on data obtained in trials with very low certainty according to GRADE and should therefore be interpreted cautiously. Until conclusive evidence is obtained, the standard of care according to ESVS guidelines should not be abandoned.

Comparing GIPAW with numerically exact chemical shieldings: The role of two-center contributions to the induced current.

In this study, we benchmark density functional theory gauge-including projector-augmented-wave (GIPAW) chemical shieldings against molecular shieldings for which basis set completeness has been achieved [Jensen et al., Phys. Chem. Chem. Phys. 18, 21145 (2016)]. We demonstrate the importance of two-center corrections for GIPAW hydrogen shieldings. For the other nuclei studied, standard GIPAW is sufficiently accurate. We find that GIPAW can be pushed to closely approach the basis set limit. The only source of small inaccuracies lies in the contribution to the shielding that is caused by surface currents, which we estimate comparing GIPAW susceptibilities to converged molecular magnetizabilities.

Carotid endarterectomy with patch angioplasty versus primary closure in patients with symptomatic and significant stenosis: a systematic review with meta-analyses and trial sequential analysis of randomized clinical trials.

BACKGROUND: Patch angioplasty in conventional carotid endarterectomy is suggested to reduce the risk of restenosis and recurrent ipsilateral stroke compared with primary closure. A systematic review of randomized clinical trials is needed to compare outcomes (benefits and harms) of both techniques. METHODS: Searches (CENTRAL, PubMed/MEDLINE, EMBASE, and other databases) were last updated 3rd of January 2021. We included randomized clinical trials comparing carotid endarterectomy with patch angioplasty versus primary closure of the arterial wall in patients with a symptomatic and significant (> 50%) carotid stenosis. Primary outcomes are defined as all-cause mortality and serious adverse events. RESULTS: We included 12 randomized clinical trials including 2187 participants who underwent 2335 operations for carotid stenosis comparing carotid endarterectomy with patch closure (1280 operations) versus carotid endarterectomy with primary closure (1055 operations). Meta-analysis comparing carotid endarterectomy with patch angioplasty versus carotid endarterectomy with primary closure may potentially decrease the number of patients with all-cause mortality (RR 0.53; 95% CI 0.26 to 1.08; p = 0.08, best-case scenario for patch), serious adverse events (RR 0.73; 95% CI 0.56 to 0.96; p = 0.02, best-case scenario for patch), and the number of restenosis (RR 0.41; 95% CI 0.23 to 0.71; p < 0.01). Trial sequential analysis demonstrated that the required information sizes were far from being reached for these patient-important outcomes. All the patient-relevant outcomes were at low certainty of evidence according to The Grading of Recommendations Assessment, Development, and Evaluation. CONCLUSIONS: This systematic review showed no conclusive evidence of a difference between carotid endarterectomy with patch angioplasty versus primary closure of the arterial wall on all-cause mortality, < 30 days mortality, < 30 days stroke, or any other serious adverse events. These conclusions are based on data from 15 to 35 years ago, obtained in trials with very low certainty according to GRADE, and should be interpreted cautiously. Therefore, we suggest conducting new randomized clinical trials patch angioplasty versus primary closure in carotid endarterectomy in symptomatic patients with an internal carotid artery stenosis of 50% or more. Such trials ought to be designed according to the Standard Protocol Items: Recommendations for Interventional Trials statement (Chan et al., Ann Intern Med 1:200-7, 2013) and reported according to the Consolidated Standards of Reporting Trials statement (Schulz et al., 7, 2010). Until conclusive evidence is obtained, the standard of care according to guidelines should not be abandoned. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42014013416 . Review protocol publication 2019 DOI: https://doi.org/10.1136/bmjopen-2018-026419 .

Eversion technique versus conventional endarterectomy with patch angioplasty in carotid surgery: protocol for a systematic review with meta-analyses and trial sequential analysis of randomised clinical trials.

INTRODUCTION: Traditional carotid endarterectomy is considered to be the standard technique for prevention of a new stroke in patients with a symptomatic carotid stenosis. Use of patch angioplasty to restore the arterial wall after longitudinal endarterectomy is, to date, not unequivocally proven to be superior to eversion technique. A systematic review is needed for evaluation of benefits and harms of the eversion technique versus the traditional endarterectomy with patch angioplasty in patients with symptomatic carotid stenosis. METHODS AND OUTCOMES: The review will be conducted according to this protocol following the recommendations of the 'Cochrane Handbook for Systematic Reviews' and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Randomised clinical trials comparing eversion technique versus endarterectomy with patch angioplasty in patients with a symptomatic stenosis of the internal carotid artery will be included. Primary outcomes are all-cause mortality rate, health-related quality of life and serious adverse events. Secondary outcomes are 30-day stroke and mortality rate, symptomatic arterial restenosis or occlusion and non-serious adverse events. The databases Cochrane Central Register of Controlled Trials, PubMed/MEDLINE and EMBASE will be searched (November 2019). We will primarily base our conclusions on meta-analyses of trials with overall low-risk of bias. We will use trial sequential analysis to assist the evaluation of imprecision in Grading of Recommendations, Assessment, Development and Evaluation. However, if pooled point estimates of all trials are similar to pooled point estimates of trials with overall low risk of bias and there is lack of a statistical significant interaction between estimates from trials with overall high risk of bias and trials with overall low risk of bias we will consider the trial sequential analysis adjusted precision of the estimate achieved in all trials as the result of our meta-analyses. ETHICS AND DISSEMINATION: The proposed systematic review will collect and analyse data from published studies, therefore, ethical approval is not required. The results of the review will be disseminated by publication in a peer-review journal and submitted for presentation at conferences. PROSPERO REGISTRATION NUMBER: CRD42019119361.

Eagle Syndrome: A Unique Cause of Carotid Bleeding.

Eagle syndrome is a rare aggregate of symptoms caused by an elongated styloid process. We present the unique case of bilateral vascular Eagle syndrome in a patient who experienced a unilateral acute swelling due to bleeding at the level of the right internal carotid artery. This complication has never been described before. (Level of Difficulty: Advanced.).

Assessing model-dielectric-dependent hybrid functionals on the antiferromagnetic transition-metal monoxides MnO, FeO, CoO, and NiO.

Recently, two nonempirical hybrid functionals, dielectric-dependent range-separated hybrid functional based on the Coulomb-attenuating method (DD-RSH-CAM) and doubly screened hybrid functional (DSH), have been suggested by Chen et al (2018 Phys. Rev. Mater. 2 073803) and Cui et al (2018 J. Phys. Chem. Lett. 9 2338), respectively. These two hybrid functionals are both based on a common model dielectric function approach, but differ in the way how to non-empirically obtain the range-separation parameter. By retaining the full short-range Fock exchange and a fraction of the long-range Fock exchange that equals the inverse of the dielectric constant, both DD-RSH-CAM and DSH turn out to perform very well in predicting the band gaps for a large variety of semiconductors and insulators. Here, we assess how these two hybrid functionals perform on challenging antiferromagnetic transition-metal monoxides MnO, FeO, CoO, and NiO by comparing them to other conventional hybrid functionals and the GW method. We find that single-shot DD0-RSH-CAM and DSH0 improve the band gaps towards experiments as compared to conventional hybrid functionals. The magnetic moments are slightly increased, but the predicted dielectric constants are decreased. The valence band density of states (DOS) predicted by DD0-RSH-CAM and DSH0 are as satisfactory as HSE03 in comparison to experimental spectra, however, the conduction band DOS are shifted to higher energies by about 2 eV compared to HSE03. Self-consistent DD-RSH-CAM and DSH deteriorate the results with a significant overestimation of band gaps.

Carotid endarterectomy with primary closure versus patch angioplasty in patients with symptomatic and significant stenosis: protocol for a systematic review with meta-analyses and trial sequential analysis of randomised clinical trials.

INTRODUCTION: Use of patch angioplasty in carotid endarterectomy (CEA) is suggested to reduce the risk of restenosis and recurrent ipsilateral stroke. The objective is to conduct a systematic review with meta-analysis and trial sequential analysis as well as Grading of Recommendations Assessment, Development and Evaluation (GRADE) assessments comparing the benefits and harms of CEA with primary closure of the arterial wall versus CEA with patch angioplasty in patients with a symptomatic and significant carotid stenosis. METHODS AND ANALYSIS: The review shall be conducted according to this published protocol following the recommendations of the 'Cochrane' and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Randomised clinical trials comparing CEA with primary closure of the arterial wall versus CEA with patch angioplasty (regardless of used patch materials) in human adults with a symptomatic and significant carotid stenosis will be included. Primary outcomes are all-cause mortality at maximal follow-up, health-related quality of life and serious adverse events. Secondary outcomes are symptomatic or asymptomatic arterial occlusion or restenosis, and non-serious adverse events. We will primarily base our conclusions on meta-analyses of trials with overall low risk of bias. However, if pooled point estimates of all trials are similar to pooled point estimates of trials with overall low risk of bias and there is lack of a statistical significant interaction between estimates from trials with overall high risk of bias and trials with overall low risk of bias we will consider the precision achieved in all trials as the result of our meta-analyses. ETHICS AND DISSEMINATION: The proposed systematic review will collect and analyse secondary data from published studies therefor ethical approval is not required. The results of the systematic review will be disseminated by publication in a peer-review journal and submitted for presentation at relevant conferences. PROSPERO REGISTRATION NUMBER: CRD42014013416.

Case Series about the Changed Antiplatelet Protocol for Carotid Endarterectomy in a Teaching Hospital: More Patients with Complications?

Introduction In the Netherlands, clopidogrel monotherapy increasingly replaces acetylsalicylic acid and extended release dipyridamole as the first-choice antiplatelet therapy after ischemic stroke. It is unknown whether the risk of peri- and postoperative hemorrhage in carotid artery surgery is higher in patients using clopidogrel monotherapy compared with acetylsalicylic acid and extended release dipyridamole. We therefore retrospectively compared occurrence of perioperative major and (clinical relevant) minor bleedings during and after carotid endarterectomy of two groups using different types of platelet aggregation inhibition after changing our daily practice protocol in our center. Material and Methods A consecutive series of the most recent 80 carotid endarterectomy patients (November 2015-August 2017) treated with the new regime (clopidogrel monotherapy) were compared with the last 80 (January 2012-November 2015) consecutive patients treated according to the old protocol (acetylsalicylic acid and dipyridamole). The primary endpoint was any major bleeding during surgery or in the first 24 to 72 hours postoperatively. Secondary outcomes within 30 days after surgery included minor (re)bleeding postoperative stroke with persistent or transient neurological deficit, persisting or transient neuropraxia, asymptomatic restenosis or occlusion, (transient) headache. Reporting of this study is in line with the 'Strengthening the Reporting of Observational Studies in Epidemiology' statement. Results Although statistical differences were observed, from a clinical perspective both patients groups were comparable. Postoperative hemorrhage requiring reexploration for hemostasis occurred in none of the 80 patients in the group of the clopidogrel monotherapy (new protocol) and it occurred in one of the 80 patients (1%) who was using acetylsalicylic acid and dipyridamole (old protocol). In three patients (4%) in the clopidogrel monotherapy and one patient (1%) in the acetylsalicylic acid and extended release dipyridamole protocol an ipsilateral stroke was diagnosed. Conclusion In this retrospective consecutive series the incidence of postoperative ischemic complications and perioperative hemorrhage after carotid endarterectomy (CEA) seemed to be comparable in patients using clopidogrel monotherapy versus acetylsalicylic acid and extended release dipyridamole for secondary prevention after a cerebrovascular event. This study fuels the hypothesis that short- and midterm complications of clopidogrel and the combination acetylsalicylic acid and extended release dipyridamole are comparable.

Comparison of Cartilage-Scoring and Cartilage-Sparing Otoplasty: A Retrospective Analysis of Complications and Aesthetic Outcome of 1060 Ears.

BACKGROUND: Various techniques are used to correct prominent ears. The authors describe their experience with four different otoplasty techniques in 565 patients with congenital deformities of the ears (1060 ears) that were performed in their hospital during an 11-year period (2002 to 2012). METHODS: The authors divided the techniques into two groups: group I, cartilage-sparing techniques (i.e., IA, Mustardé; and IB, Furnas); and group II, cartilage-cutting techniques (i.e., IIA, Chongchet; and IIB, concha shell reduction). The authors compared early and late and minor and major complications, recurrence rates, and revision surgery. Furthermore, aesthetic outcome was scored by three different groups (consultant plastic surgeons, plastic surgery residents, and laymen) on a visual analogue scale using a blinded random selection of preoperative and postoperative photographs. RESULTS: The percentage of complications without the need for reoperation was 20 percent and 21 percent in the cartilage-sparing and cartilage-cutting groups, respectively (p = 0.44). In 6 percent of all cases, a reoperation of the otoplasty was required (7 percent and 6 percent in the cartilage-sparing and cartilage-cutting groups, respectively). Aesthetic postoperative results showed that the cartilage-cutting group scored significantly lower on postoperative shape (p = 0.04), result (p = 0.03), and satisfaction (p = 0.04) compared with the cartilage-sparing group. CONCLUSIONS: The study shows that patients who have undergone operations with cartilage-sparing or cartilage-cutting techniques have a similar rate of complications and need for reoperation. However, the cartilage-sparing techniques have a better aesthetic outcome, as judged by the different groups. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Occluded Superficial Femoral Artery Used for Emergency Reconstruction: A Consecutive Case Series about the "Proper Conduit Technique".

BACKGROUND: Deep wound infections in the groin region can result in an acute or life-threatening condition. Especially, when there is no suitable vein available because of many reasons (e.g., previous bypass surgery, small vessel diameter). Synthetic prosthesis is not always the "first-choice technique" because of contamination or infection. It was ad hoc hypothesized in an acute setting that a segment of an occluded superficial femoral artery (SFA) could be used as a conduit in combination with eversion technique, known from carotid surgery. METHODS: The clinical experience with the use of an occluded SFA as an autograft for arterial reconstruction is described in this consecutive case series, and the available level of evidence was assessed for each consideration and rationale aspect of this technique. This study was conducted and reported in line with the consensus-based clinical case report guideline (CARE guideline 2016). Data of 5 patients were retrieved from the electronic patient files and were analyzed retrospectively. Patients were all invited for follow up at the outpatient department for physical examination and duplex ultrasound. Literature was searched for this technique by using online library systems (PubMed, Embase, and the Cochrane Library). A medical drawer made a schematic overview of the operation steps of this technique. RESULTS: Five patients with a history of vascular disease underwent an open revascularization for which an occluded SFA segment was harvested. An eversion endarterectomy of the selected SFA segment was used as a "proper conduit" to restore the blood flow to the limb. Postoperatively, best medical treatment was (re)started, and no major complications were assessed. CONCLUSIONS: The "proper conduit technique" of an occluded superficial femoral artery segment seems to be a feasible method for emergency and elective treatment of vascular patients with (potential) groin region difficulties (level of evidence 4).

Reproducibility in density functional theory calculations of solids.

The widespread popularity of density functional theory has given rise to an extensive range of dedicated codes for predicting molecular and crystalline properties. However, each code implements the formalism in a different way, raising questions about the reproducibility of such predictions. We report the results of a community-wide effort that compared 15 solid-state codes, using 40 different potentials or basis set types, to assess the quality of the Perdew-Burke-Ernzerhof equations of state for 71 elemental crystals. We conclude that predictions from recent codes and pseudopotentials agree very well, with pairwise differences that are comparable to those between different high-precision experiments. Older methods, however, have less precise agreement. Our benchmark provides a framework for users and developers to document the precision of new applications and methodological improvements.

Finite-field implementation of NMR chemical shieldings for molecules: direct and converse gauge-including projector-augmented-wave methods.

Two finite-field implementations for the calculation of chemical shieldings of molecular systems using a plane-wave basis set and the Gauge-Including Projector-Augmented-Wave method are presented. The direct approach mimics the nuclear magnetic resonance experiment in that it puts the molecule in a uniform magnetic field and obtains shieldings from the current response. The other is based on the recently introduced "converse method" [T. Thonhauser, D. Ceresoli, A. A. Mostofi et al., J. Chem. Phys. 131, 101101 (2009)]. In both methods two-center contributions to the shieldings can be included via a numerically simple augmentation construction. Results obtained with both methods are discussed as well as (dis)similarities in their behaviors.

Periodic projector augmented wave density functional calculations on the hexachlorobenzene crystal and comparison with the experimental multipolar charge density model.

The projector augmented wave (PAW) methodology has been used to calculate a high precision electron density distribution ρ(r) for the hexachlorobenzene crystal phase. Implementing the calculation of the crystallographic structure factors in the VASP code has permitted one to obtain the theoretical multipolar ρ(r). This electron density is compared with both the DFT electron density and the experimental multipolar model obtained from high-resolution X-ray diffraction data. This comparison has been carried out in intra- and intermolecular regions within the framework of the quantum theory of atoms-in-molecules (QTAIM) developed by Bader and co-workers. The characterization of the electron density in both C-Cl and Cl···Cl regions, as well as within the atomic basins, shows similar features for the three models. As a consequence, the observation of charge depletion and charge concentration regions around the halogen nuclei (along the C-Cl bonding axis and in the perpendicular plane, respectively) underlines the nature of halogen bonding in terms of electrophilic and nucleophilic interactions.

Proximity of iron pnictide superconductors to a quantum tricritical point.

In several materials, unconventional superconductivity appears nearby a quantum phase transition where long-range magnetic order vanishes as a function of a control parameter like charge doping, pressure or magnetic field. The nature of the quantum phase transition is of key relevance, because continuous transitions are expected to favour superconductivity, due to strong fluctuations. Discontinuous transitions, on the other hand, are not expected to have a similar role. Here we determine the nature of the magnetic quantum phase transition, which occurs as a function of doping, in the iron-based superconductor LaFeAsO(1-x)F(x). We use constrained density functional calculations that provide ab initio coefficients for a Landau order parameter analysis. The outcome is intriguing, as this material turns out to be remarkably close to a quantum tricritical point, where the transition changes from continuous to discontinuous, and several susceptibilities diverge simultaneously. We discuss the consequences for superconductivity and the phase diagram.

Hydrogen bonding and chemical shift assignments in carbazole functionalized isocyanides from solid-state NMR and first-principles calculations.

Carbazole functionalized polyisocyanides are known to exhibit excellent electronic properties (E. Schwartz, et al., Chemistry of Materials, 2010, 22, 2597). The functionalities and properties of such materials crucially depend on the organization and stability of the polymer structure. We combine solid-state Nuclear Magnetic Resonance (NMR) experiments with first-principles calculations of isotropic chemical shifts, within the recently developed converse approach, to rationalize the origin of isotropic chemical shifts in the crystalline monomer l-isocyanoalanine 2-(9H-carbazol-9-yl) ethyl amide (monomer 1) and thereby gain insight into the structural organization of its polymer (polymer 2). The use of state-of-the-art solid-state NMR experiments combined with Density Functional Theory (DFT) based calculations allows an unambiguous assignment of all proton and carbon resonances of the monomer. We were able to identify the structure stabilising interactions in the crystal and understand the influence of the molecular packing in the crystal structure on the chemical shift data observed in the NMR spectra. Here the Nuclear Independent Chemical Shift (NICS) approach allows discriminating between 'physical' interactions amongst neighboring molecules such as ring-current effects and 'chemical' interactions such as hydrogen bonding. This analysis reveals that the isocyanide monomer is stabilized by multiple hydrogen bonds such as a bifurcated hydrogen bond involving -N-H, -C-H and O=C- moieties and Ar-H···C≡N- hydrogen bonding (Ar = aromatic group). Based on the geometrical arrangement it is postulated that the carbazole units are involved in the weak σ-π interactions giving rise to a Herringbone packing of the molecules. The chemical shift analysis of the polymer spectra readily establishes the existence of N-H···O=C hydrogen bonds despite the limited resolution exhibited by the polymer spectra. It is also elucidated that the relative arrangement of the carbazole units in the polymer differs significantly from that of the monomer.

Natural Orbitals for Wave Function Based Correlated Calculations Using a Plane Wave Basis Set.

We demonstrate that natural orbitals allow for reducing the computational cost of wave function based correlated calculations, especially for atoms and molecules in a large box, when a plane wave basis set under periodic boundary conditions is used. The employed natural orbitals are evaluated on the level of second-order Møller-Plesset perturbation theory (MP2), which requires a computational effort that scales as [Formula: see text](N(5)), where N is a measure of the system size. Moreover, we find that a simple approximation reducing the scaling to [Formula: see text](N(4)) yields orbitals that allow for a similar reduction of the number of virtual orbitals. The MP2 natural orbitals are applied to coupled-cluster singles and doubles (CCSD) as well as full configuration interaction Quantum Monte Carlo calculations of the H2 molecule to test our implementation. Finally, the atomization energies of the LiH molecule and solid are calculated on the level of MP2 and CCSD.

Second-order Møller-Plesset perturbation theory applied to extended systems. II. Structural and energetic properties.

Results for the lattice constants, atomization energies, and band gaps of typical semiconductors and insulators are presented for Hartree-Fock and second-order Moller-Plesset perturbation theory (MP2). We find that MP2 tends to undercorrelate weakly polarizable systems and overcorrelates strongly polarizable systems. As a result, lattice constants are overestimated for large gap systems and underestimated for small gap systems. The volume dependence of the MP2 correlation energy and the dependence of the MP2 band gaps on the static dielectric screening properties are discussed in detail. Moreover, the relationship between MP2 and the G(0)W(0) quasiparticle energies is elucidated and discussed. Finally, we demonstrate explicitly that the correlation energy diverges with decreasing k-point spacing for metals.

A solid-state NMR and DFT study of compositional modulations in Al(x)Ga(1-x)As.

We have conducted (75)As and (69)Ga Nuclear Magnetic Resonance (NMR) experiments to investigate order/disorder in Al(x)Ga(1-x)As lift-off films with x∼ 0.297 and 0.489. We were able to identify all possible As(Al(n)Ga(4-n)) sites with n = 0-4 coordinations in (75)As NMR spectra using spin-echo experiments at 18.8 Tesla. This was achieved by employing high rf field strengths using a small solenoid coil and an NMR probe specifically designed for this purpose. Spectral deconvolution, using an evolutionary algorithm, complies with the absence of long-range order if a CuAu based order parameter is imposed. An unconstrained fit shows a deviation of the statistics imposed by this type of ordering. The occupational disorder in the Ga and Al positions is reflected in a distribution of the Electric Field Gradients (EFGs) experienced at the different arsenic sites. We established that this can be modelled by summing the effects of the first coordination sphere and a Czjzek type distribution resulting from the compositional variation in the Al/Ga sub-lattice in the higher coordination spheres. (69)Ga 3QMAS and nutation data exclude the presence of highly symmetric sites and also show a distribution in EFG. The experimentally obtained quadrupolar interactions are in good agreement with calculations based on Density Functional Theory (DFT). Using additivity of EFG tensors arising from distant charge perturbations, we could use DFT to model the EFG distributions of the n = 0-4 sites, reproducing the Czjzek and extended Czjzek distributions that were found experimentally. On the basis of these calculations we conclude that the (75)As quadrupolar interaction is sensitive to compositional modulations up to the 7th coordination shell in these systems.

Making the random phase approximation to electronic correlation accurate.

We show that the inclusion of second-order screened exchange to the random phase approximation allows for an accurate description of electronic correlation in atoms and solids clearly surpassing the random phase approximation, but not yet approaching chemical accuracy. From a fundamental point of view, the method is self-correlation free for one-electron systems. From a practical point of view, the approach yields correlation energies for atoms, as well as for the jellium electron gas within a few kcal/mol of exact values, atomization energies within typically 2-3 kcal/mol of experiment, and excellent lattice constants for ionic and covalently bonded solids (0.2% error). The computational complexity is only O(N(5)), comparable to canonical second-order Møller-Plesset perturbation theory, which should allow for routine calculations on many systems.