Negative / Null Result Report
· 2019 · The Brown University Psychopharmacology Update
Six weeks of D‐cycloserine treatment for patients with depression who had responded to doses of ketamine did not improve depressive symptoms compared with placebo, a study has found. D‐cycloserine was found to maintain the anti‐suicidal…
View details →DOI: 10.1002/pu.30506 Negative / Null Result ReportOpen accessComputer Science
C. Abel, N. J. Ayres, G. Ban et al. · 2017 · arXiv
We report on a search for ultra-low-mass axion-like dark matter by analysing the ratio of the spin-precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms for an axion-induced oscillating electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range $10^{-24}~\textrm{eV} \le m_a \le 10^{-17}~\textrm{eV}$. Our null result sets the first laboratory constraints on the coupling of axion dark matter to gluons, which improve on astrophysical limits by up to 3 orders of magnitude, and also im
Negative / Null Result ReportOpen accessEconomics, Econometrics and Finance
Ruiwu Liu · 2021 · arXiv
Acemoglu and Johnson (2007) put forward the unprecedented view that health improvement has no significant effect on income growth. To arrive at this conclusion, they constructed predicted mortality as an instrumental variable based on the WHO international disease interventions to analyse this problem. I replicate the process of their research and eliminate some biases in their estimate. In addition, and more importantly, we argue that the construction of their instrumental variable contains a violation of the exclusion restriction of their instrumental variable. This negative correlation betw
Negative / Null Result Report
Cui L, Harrison L, Liu J · 2022 · Preprint
Many studies have failed to replicate the disfluency effect (i.e. disfluent font better than fluent font) on Cognitive Reflection Test (CRT) performance shown in Alter et al. (2007). Those studies manipulated perceptual disfluency using…
View details →DOI: 10.31234/osf.io/qdxw3 Negative / Null Result Report
Katsuhiko Naruse, Itsuko Okada, Masahiko Ogawa et al. · 2020 · International Journal of Gynecology & Obstetrics
Intra‐anal swabbing for GBS in pregnant women did not improve the detection rate compared to perianal swabbing, but increased the detection of ESBL‐producing E.coli .
View details →DOI: 10.1002/ijgo.13238 Negative / Null Result ReportOpen accessPhysics
Ulrich Kolb, Isabelle Baraffe · 1999 · arXiv
Using improved, up-to-date stellar input physics tested against observations of low-mass stars and brown dwarfs we calculate the secular evolution of low-mass donor cataclysmic variables (CVs), including those which form with a brown dwarf donor. Our models confirm the mismatch between the calculated minimum period (Pmin ~ 70 min) and the observed short-period cut-off (~ 80 min) in the CV period histogram. We find that tidal and rotational corrections applied to the one-dimensional stellar structure equations have no significant effect on the period minimum. Theoretical period distributions sy
Negative / Null Result ReportOpen accessComputer Science
Varun Kotte · 2026 · arXiv
Prompt-only, single-step LLM query rewriting, where a rewrite is generated from the query alone without retrieval feedback, is commonly used in production RAG pipelines, but its effect on dense retrieval is poorly understood. We present a systematic empirical study across three BEIR benchmarks, two dense retrievers, and multiple training configurations, and find strongly domain-dependent behavior: rewriting degrades nDCG@10 by 9.0 percent on FiQA, improves it by 5.1 percent on TREC-COVID, and has no significant effect on SciFact. We identify a consistent mechanism: degradations co-occur with r
Negative / Null Result ReportOpen accessBiology (General)
Qiaoli Wang, Wenpei Wang, Yonghui Wang et al. · 2024 · Journal of Fungi
Manganese is one of the trace elements necessary for organisms to maintain normal biological activities and is also a cofactor for manganese superoxide dismutase (Mn-SOD) and manganese peroxidase (MnP). In order to find a simple and effective method to rejuvenate the degenerated V. volvacea strains, we explored the effect of the exogenous addition of MnSO 4 on the antioxidant vigour and productivity of degenerated strains of V. volvacea . The results showed that the exogenous MnSO 4 had no significant effect on the non-degenerated strain T0, but it could effectively increase the mycelial growt
View details →DOI: 10.3390/jof10120825 Negative / Null Result ReportOpen accessPlant culture
J. Harb, A. A. Saquet, R. Bisharat et al. · 2012 · Journal of Applied Botany and Food Quality
Biochemical and quality changes of sweet cherries cv. Regina were assessed over three consecutive years after storage in different modified atmosphere packaging (MAP) liners, with or without hydrocooling, compared to regular atmosphere (RA) storage. All plastic liners used in the experiment resulted in CO2-enrichment and O2-reduction inside packages, with the following impact on fruit quality after five weeks of storage: improved retention of fruit firmness and red color of skin, no significant effect on acidity and total soluble solids, and minimal loss of fruit weight. Fruit decay was absent
Negative / Null Result ReportOpen accessElementary particle physics
John K. Webb, Chung-Chi Lee, Dinko Milaković · 2022 · Universe
Recent advances in spectroscopic instrumentation and calibration methods dramatically improve the quality of quasar spectra. Supercomputer calculations show that, at high spectral resolution, procedures used in some previous analyses of spacetime variations of fundamental constants are likely to generate spurious measurements, biased systematically towards a null result. Developments in analysis methods are also summarised and a prescription given for the analysis of new and forthcoming data.
View details →DOI: 10.3390/universe8050266 Negative / Null Result ReportOpen accessMedicine
Abraham D. Flaxman, Riley Hazard, Ian Riley et al. · 2020 · BMC Medicine
Abstract We recently published in BMC Medicine an evaluation of the comparative diagnostic performance of InSilicoVA, a software to map the underlying causes of death from verbal autopsy interviews. The developers of this software claim to have failed to replicate our results and appear to have also failed to locate our replication archive for this work. In this Correspondence, we provide feedback on how this might have been done more usefully and offer some suggestions to improve future attempts at reproducible research. We also offer an alternative interpretation of the results presented by
View details →DOI: 10.1186/s12916-020-01517-w Negative / Null Result ReportOpen accessNeurosciences. Biological psychiatry. Neuropsychiatry
Maximiliano A. Hawkes, Mauricio F. Farez, Ismael L. Calandri et al. · Arquivos de Neuro-Psiquiatria
ABSTRACT Lack of stroke awareness and slow activation of emergency medical services (EMS) are frequently reported reasons for delayed arrival to the hospital. We evaluated these variables in our population. Methods Review of hospital records and structured telephone interviews of 100 consecutive stroke patients. Forward stepwise logistic regression was used for the statistical analysis. Results Seventy patients (75%) arrived at the hospital 4.5 hours after stroke symptoms onset. The use of EMS did not improve arrival times. Most patients who recognized their symptoms did not use EMS (p < 0.02)
View details →DOI: 10.1590/0004-282x20160142 Negative / Null Result ReportOpen accessBotany
Yuliang Liu, Xinye Liu, Xue Wang et al. · 2020 · BMC Plant Biology
Abstract Background As global warming becomes increasingly severe, it is urgent that we enhance the heat tolerance of crops. We previously reported that Arabidopsis thaliana PHOSPHOINOSITIDE-SPECIFIC PHOSPHOLIPASE C9 (AtPLC9) promotes heat tolerance. Results In this study, we ectopically expressed AtPLC9 in rice to examine its potential to improve heat tolerance in this important crop. Whereas AtPLC9 did not improve rice tolerance to salt, drought or cold, transgenic rice did exhibit greater heat tolerance than the wild type. High-throughput RNA-seq revealed extensive and dynamic transcriptome
View details →DOI: 10.1186/s12870-020-02709-5 Negative / Null Result ReportOpen accessMedicine (General)
MM. Tahmasbi, F. Farahmand , AA. Amis · 1999 · Acta Medica Iranica
The resistant* of pateSa against lateral displacement (Le. the stability), was studied tinder a range of conditions in vitro, at a range of knee flexion angles. Muscle forces were applied in physiological directions along the separate quadriceps muscles. Normal muscle actions with constant tension showed constant patellar stability up to sixty degrees knee flexion, and then a significant increase at ninety degrees. A pathological knee was simulated by relaxing vastus medians, and ■ lateral stability then dropped by 47%. Isolated rttlnaeular release in the pathological knee did not improv
Negative / Null Result ReportOpen accessPsychology
Stephanie M Sherman, Timothy P Buckley, Elsa Baena et al. · 2016 · Frontiers in Psychology
Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants
View details →DOI: 10.3389/fpsyg.2016.01764 Negative / Null Result ReportOpen accessMicrobiology
Amanda Louise White, Gregory Jaye Bix · 2023 · Biomolecules
Therapeutic angiogenesis has long been considered a viable treatment for vasculature disruptions, including cerebral vasculature diseases. One widely-discussed treatment method to increase angiogenesis is vascular endothelial growth factor (VEGF) A. In animal models, treatment with VEGFA proved beneficial, resulting in increased angiogenesis, increased neuronal density, and improved outcome. However, VEGFA administration in clinical trials has thus far failed to replicate the promising results seen in animal models. The lack of beneficial effects in humans and the difficulty in medicinal trans
View details →DOI: 10.3390/biom13040702 Negative / Null Result ReportOpen accessInternal medicine
Dae-Yeon Kim, Hee-Soon Park, Dong-Jae Han et al. · 2013 · Kidney Research and Clinical Practice
Renal failure caused by scrub typhus is known to be reversible. In most cases, renal function is almost fully restored after appropriate antibiotic treatment. A 71-year-old man was diagnosed with scrub typhus complicated by renal failure. A renal biopsy revealed histopathologic findings consistent with acute tubulointerstitial nephritis. Renal function did not improve 18 months after discharge and the patient required continuous hemodialysis. Although severe renal failure requiring dialysis is a rare complication of scrub typhus, we describe a case of scrub typhus requiring maintenance hemodia
View details →DOI: 10.1016/j.krcp.2013.09.003 Negative / Null Result ReportOpen accessNeoplasms. Tumors. Oncology. Including cancer and carcinogens
Michele Bottosso, Gaia Griguolo, Severine Guiu et al. · 2025 · npj Breast Cancer
Abstract Brain metastases (BMs) are a common complication of advanced breast cancer (BC), and their management has significantly evolved. We evaluated the clinical impact of these changes dividing patients diagnosed with BCBMs at three Institutions according to year of BMs diagnosis: 2000-2007 (group A), 2008-2014 (group B) and 2015-2022 (group C). Stereotactic radiotherapy increased (p < 0.001), and WBRT decreased (p = 0.010) over time. Among HER2+ BC patients, more received anti-HER2 therapy after BM diagnosis in recent years (p < 0.011). Overall survival (OS) did not improve in the entire c
View details →DOI: 10.1038/s41523-025-00735-w Negative / Null Result ReportOpen accessOphthalmology
Jemal Zeberga Shifa, Alemayehu Mekonnen Gezmu, Gezahen Negusse Ayane et al. · 2019 · The Pan-American Journal of Ophthalmology
A 22-year-old female patient was diagnosed to have HIV and treated by highly active antiretroviral therapy (HAART) since 2012 had developed a reduction of vision in both eyes secondary to cataract. The cataract was extracted from both eyes with no immediate postoperative complication. During follow-up, it was recognized that she had had bilateral Stage 3 macular hole in both eyes. The visual acuity in both eyes was 6/60 which did not improve with application of pinhole. Pars plana vitrectomy was done and sealed the macular hole in the left eye. The visual acuity remained the same in both eyes
View details →DOI: 10.4103/pajo.pajo_15_19 Negative / Null Result ReportOpen accessDiseases of the musculoskeletal system
Alexander C. Lehn, Cullen O'Gorman, Sarah Olson et al. · 2017 · Tremor and Other Hyperkinetic Movements
Background: Orthostatic tremor (OT) was first described in 1977. It is characterized by rapid tremor of 13–18 Hz and can be recorded in the lower limbs and trunk muscles. OT remains difficult to treat, although some success has been reported with deep brain stimulation (DBS). Case Report: We report a 68-year-old male with OT who did not improve significantly after bilateral thalamic stimulation. Discussion: Although some patients were described who improved after DBS surgery, more information is needed about the effect of these treatment modalities on OT, ideally i
View details →DOI: 10.7916/d8280jhr Negative / Null Result Report
Carolyn M Moffa, William Weintraub, Rocco A DeMaio et al. · 2011 · Circulation: Cardiovascular Quality and Outcomes
Background: The burden of acute heart failure (HF) remains formidable. Length of stay (LOS) must be minimized to control costs, while still maintaining positive outcomes. Inappropriate diagnoses and the lack of coordinated care remain…
View details →DOI: 10.1161/circoutcomes.4.suppl_1.ap142 Negative / Null Result Report
V. Yu. Petrov, I. N. Lavrentyeva, V. V. Vdovin et al. · 2024 · Pediatric Hematology/Oncology and Immunopathology
Hemophilia A presents a serious problem, especially in its severe and inhibitor forms, leading to severe bleeding and complications. The importance of studying the effectiveness and safety of new treatment approaches, particularly…
View details →DOI: 10.24287/1726-1708-2024-23-1-99-107 Negative / Null Result Report
Henry Lam · 2025 · Management Science
When the underlying probability distribution in a stochastic optimization is observed only through data, various data-driven formulations have been studied to obtain approximate optimal solutions. We show that no such formulations can, in…
View details →DOI: 10.1287/mnsc.2024.04482 Negative / Null Result Report
Katie Smithers · 2020 · Veterinary Evidence
PICO question In cats with traumatic coxofemoral injury, does total hip replacement (THR) offer improved outcome when compared with femoral head and neck excision (FHNE) arthroplasty? Clinical bottom line Category of research question…
View details →DOI: 10.18849/ve.v5i4.347 Negative / Null Result Report
David Mills · 2017 · Veterinary Evidence
Therapy and prognosis are entailed by the diagnosis: the holistic success of the EBVM approach therefore firmly and critically rests on diagnostic accuracy.Unfortunately, medical professionals do not appear to be very accurate with…
View details →DOI: 10.18849/ve.v2i3.147 Negative / Null Result Report
Pachara Pearodwong, Nithitad Jiebna, Padet Tummaruk · 2024 · The Thai Journal of Veterinary Medicine
This study examined the impact of intramuscular administration of tolfenamic acid 10 min before artificial insemination (AI) on serum PGF2α levels and reproductive performance in gilts and sows. In Experiment I, 20 gilts were divided into…
View details →DOI: 10.56808/2985-1130.3755 Negative / Null Result Report
Claire M. Douglas, Marnie Newell, Susan Goruk et al. · 2025 · PLOS One
Supplementation of omega-3 (n-3) polyunsaturated fatty acids has been associated with reduced side effects and improved quality of life (QoL) in breast cancer patients receiving chemotherapy. The current study reports secondary outcomes…
View details →DOI: 10.1371/journal.pone.0322178 Negative / Null Result ReportOpen accessPhysics
Ulrich H. E. Hansmann · 1997 · arXiv
We discuss the use of Tsallis generalized mechanics in simulated annealing algorithms. For a small peptide it is shown that older implementations are not more effective than regular simulated annealing in finding ground state configurations. We propose a new implementation which leads to an improvement over regular simulated annealing.
Negative / Null Result Report
Anika Jantzen, Miriam Opoku-Pare, Katharina Ruf et al. · 2014 · European Respiratory Journal
Introduction: Exercise and habitual physical activity are important components in the care of patients with cystic fibrosis (CF). Regular exercise and physical activity improve physical fitness, exercise tolerance, quality of life and…
View details →DOI: 10.1183/13993003/erj.44.suppl_58.p1971 Negative / Null Result ReportOpen accessMathematics
Yoav Zeevi, Sofi Astashenko, Liad Mudrik et al. · 2020 · arXiv
The field of psychological sciences has been grappling with the replicability crisis. Various issues have been identified as potential sources of this problem. We bring to light a potential source that has largely been overlooked and demonstrate its significant contribution to the problem: the practice of multiple comparisons. We analyzed 88 papers from the Reproducibility Project in Psychology and found that multiple results are commonly reported in a single paper, ranging from 4 to 730 (M=77.7), without multiple comparison adjustments. We retroactively applied such an adjustment using a hier