About

Tianyi Niu is an Assistant Professor of Neurosurgery and a Clinician Educator at Brown University. He completed his MD at the Medical College of Wisconsin in 2012 and earned a BS from the University of Pittsburgh in 2007. His professional focus is within the field of neurosurgery, and he is affiliated with Brown University, contributing to both clinical practice and education in this specialty.

Research topics

• Surgery
• Medicine
• Internal medicine
• Pathology
• Emergency medicine
• Radiology
• Environmental health
• Physical therapy

Selected publications

• Unraveling the size-dependent toxicity mechanisms of polystyrene microplastics on coral symbiotic Symbiodiniaceae: Integrated physiological and transcriptomic perspectives

  Marine Pollution Bulletin · 2026-04-06

  article
  PublisherDOI

• National Trends in Time to Surgery for Traumatic Spinal Cord Injury in the United States: An Analysis of the National Trauma Data Bank

  Journal of Neurotrauma · 2026-01-13

  article

  The current guidelines recommend that patients with spinal cord injury (SCI) undergo rapid decompressive surgery, ideally within 24 h, to reduce cord ischemia and improve outcomes. National trends in treatment times in the United States, and the factors limiting the timely surgical management of SCI, remain incompletely understood. A retrospective review of the National Trauma Data Bank (NTDB) from 2017 to 2021, which encompasses the years following the publication of the Arbeitsgemeinschaft für Osteosynthesefragen Spine guidelines suggesting early surgery, was performed. The included patients had sustained SCI requiring surgical management, were aged >18 years, were treated at a level I or II trauma center, and had no major trauma-related cranial, abdominal, or thoracic surgery prior to spine surgery. Mixed-effects models were used to identify the key factors at the patient and facility levels associated with time to surgery. The final cohort included 19,513 patients, of which 3,894 (19.9%) underwent surgery within 8 h and 10,634 (54.5%) underwent surgery within 24 h. The average time to surgery for patients admitted in 2018–2019 did not differ from 2017, whereas patients admitted in 2020 (−4.58 h, 95% confidence interval [CI] [−6.09, −3.07], p < 0.001) and 2021 (−2.17 h, 95% CI [−3.65, −0.68], p = 0.004) had significantly shorter times to surgery. Older patients experienced delays of 0.25 h per year of age (95% CI [0.22, 0.27], p < 0.001). Medicare status delayed surgery by 5.81 h (95% CI [4.81, 6.81], p < 0.001). When compared with patients arriving by helicopter ambulance, patients who self-transported (11.57 h, 95% CI [9.26, 13.90], p < 0.001) or were transported by ground ambulance (5.93 h, 95% CI [4.90, 6.96], p < 0.001) experienced significant delays. Pre-frail (5.88 h, 95% CI [5.02, 6.74], p < 0.001) or frail (10.15 h, 95% CI [8.62, 11.68], p < 0.001) patients by the 11-item modified frailty index had increased time to surgery. Patients with cervical injuries had significantly longer times to surgery compared with those with cervicothoracic (−3.42 h, 95% CI [−5.56, −1.28], p = 0.002) or thoracic injuries (−6.29 h, 95% CI [−7.54, −5.05], p < 0.001). Treatment at teaching hospitals (−1.18 h, 95% CI [−2.18, −0.37], p = 0.001) and level I trauma centers (1.41 h, 95% CI [−2.50, −0.53], p = 0.003) reduced the time to surgery in comparison with non-teaching and level II trauma hospitals. In summary, older age, pre-existing frailty, cervical injury, Medicare insurance status, and transportation by ground ambulance or self-transportation are associated with prolonged time to surgery, while treatment at teaching hospitals and level I trauma centers is linked to more rapid intervention. These results suggest that rapid emergency medical systems transport and management at high-resource trauma centers may minimize surgical delays. Despite improvements in later years, nearly half of patients did not meet 24-h operative standards, and only one in five met 8-h targets, underscoring persistent variability in practice patterns and opportunities to better align care with the established guidelines.

  PublisherDOI

• Metastatic Spinal Tumor Frailty Index and New England Spinal Metastasis Score Show the Most Consistent Performance for Short-Term Postoperative Outcomes: Single-Center Validation in 114 Patients

  North American Spine Society Journal (NASSJ) · 2026-04-01

  articleOpen access
  PublisherDOI

• Multifunctional composite microbial inoculants in sustainable agriculture: Design, carriers and field application

  Soil Ecology Letters · 2026-04-18

  article1st author
  PublisherDOI

• Multilevel Lateral Lumbar Interbody Fusion for Symptomatic Spondylotic Stenosis and Severe Disc Degeneration Without Scoliosis: Single-Institutional Case Series and Lessons Learned

  The International Journal of Spine Surgery · 2026-03-31

  articleOpen access

  <sec><title>Background</title> Posterior decompression for degenerative lumbar spinal stenosis (DLSS) carries approach-related morbidity. In this study, we hypothesized that multilevel lateral lumbar interbody fusion (LLIF) achieves effective indirect decompression with acceptable safety and patient-reported improvement among DLSS patients without scoliosis. </sec><sec><title>Methods</title> This was a single-institution retrospective case series (2016–2022) of adults with symptomatic spondylotic stenosis and severe disc degeneration without scoliosis (Cobb angle <10°) undergoing multilevel (≥2) LLIF. Patients with concurrent posterior decompression or deformity correction were excluded. Primary outcomes were radiographic decompression (central canal diameter and bilateral foraminal height), patient-reported pain and disability (visual analog scale and Oswestry Disability Index), and complications. Secondary measures included spinopelvic parameters and fusion by the Brantigan-Steffee-Fraser scale. Imaging was assessed on pre- and postoperative magnetic resonance imaging. Tests of significance included 1-sided paired <italic>t</italic> tests for parametric variables and Wilcoxon signed-rank tests otherwise. </sec><sec><title>Results</title> Twenty-five patients (mean age 65.8 years; 56% men; mean body mass index 31.2 ± 5.4) underwent 57 LLIF levels with a mean follow-up of 41.3 ± 31.6 months. Central canal diameter increased by 31% (2.2 mm absolute), and foraminal height increased 17% to 39% (2.5–13.1 mm). Lumbar lordosis improved from 39.6° to 44.8°, with PI–LL mismatch improving by 5.4°. Early fusion status (BSF-3) at the last radiological assessment (mean 7.2 months) was 91.3% (21/23 evaluated). Visual analog scale score improved from 7.1 ± 2.0 to 3.0 ± 2.4 (Δ−4.1; <italic>n</italic> = 20), and Oswestry Disability Index score improved from 65.9 ± 12.9 to 47.5 ± 19.8 (Δ−18.4; <italic>n</italic> = 17). Overall complication rate was 40% with no major events; postoperative neurological complications included transient proximal lower-extremity weakness in 4% and persistent sensory symptoms in 12%. </sec><sec><title>Conclusions</title> In carefully selected DLSS patients without scoliosis, multilevel LLIF achieved meaningful indirect decompression, substantial pain and disability improvement, and high early fusion rates with no major complications. The findings support LLIF as a viable alternative to posterior approaches. </sec><sec><title>Clinical Relevance</title> Multilevel LLIF can facilitate multilevel indirect decompression with favorable radiographic and clinical outcomes while avoiding posterior soft-tissue disruption. Routine posterior instrumentation at the index surgery may support fusion and reduce returns to the OR. </sec><sec><title>Level of Evidence</title> 4. </sec>

  PublisherOA PDFDOI

• Unmasking Racial, Ethnic, and Socioeconomic Disparities in United States Chordoma Clinical Trials: Systematic Review

  Cancers · 2025-01-12 · 1 citations

  reviewOpen access

  Background: Chordoma is a rare bone cancer with limited treatment options. Clinical trials are crucial for developing effective therapies, but their success depends on including diverse patient populations. The objective of this study was to systematically evaluate the reporting of racial, ethnic, and socioeconomic diversity in United States clinical trials exploring treatment for chordoma. Methods: A literature search was conducted through PubMed/Medline, Cochrane, Epistemonikos, and ClinicalTrials.gov databases for published US chordoma trials up until 19 August 2024. The data collected included trial characteristics and racial and ethnic data, as well as socioeconomic indicators when available. Methodological Index for Non-Randomized Studies (MINORS) and Revised Cochrane Risk-of-Bias Tool for Randomized Trials (RoB2) analyses were adopted to assess the methodological quality. The N-1 Chi-squared (χ2) test was implemented to compare the reported racial and ethnic data with the most recent US Census Bureau data. Results: Five trials involving 111 patients (median age: 63 years; 34% female) were included. Four studies (80%) were single-arm non-randomized studies with one study (25%) having a high methodological quality and three (75%) having a moderate quality based on the MINORS analysis. Most patients (91%, n = 82) were White/Caucasian, representing a proportion which was significantly higher than the reported 75% in the US population (p = 0.0005). Black/African American patients (2%, n = 2) were significantly underrepresented compared to the 14% in the US population (p = 0.0015). Regarding ethnicity, Hispanic/Latino patients (7%, n = 6) were significantly underrepresented compared to the 20% in the US population (p = 0.0021). No measures of socioeconomic status were reported. Conclusions: This systematic review highlighted the need for improved racial and ethnic diversity in chordoma trials and the better reporting of socioeconomic data. The underrepresentation of minority groups may obscure potential disparities in disease incidence, treatment access, and clinical outcomes.

  PublisherOA PDFDOI

• Polystyrene microplastics exhibit toxic effects on the widespread coral symbiotic Cladocopium goreaui

  Environmental Research · 2025-01-02 · 16 citations

  article
  PublisherDOI

• Arbuscular mycorrhizal fungi and Trichoderma harzianum alter salicylic acid–jasmonic acid balance to suppress Fusarium wilt in tomato

  Frontiers in Plant Science · 2025-11-18 · 3 citations

  articleOpen access

  Fusarium wilt, caused by Fusarium oxysporum , poses a significant challenge to tomato production, and sustainable control strategies are urgently needed. Beneficial microbes such as arbuscular mycorrhizal (AM) fungi and Trichoderma harzianum are widely applied as biocontrol agents, but their combined effects and the underlying immune mechanisms in host plants remain insufficiently understood. In this study, greenhouse experiments were conducted to evaluate the impacts of inoculation with Rhizophagus irregularis and T. harzianum , individually and together, on pathogen colonization, nutrient uptake, hormone signaling, and defense responses in tomato. Quantitative PCR revealed that both beneficial fungi significantly reduced F. oxysporum colonization in roots, yet co-inoculation did not provide additional suppression compared with single inoculations. Hormonal profiling showed that pathogen infection alone activated jasmonic acid (JA)-dominated defenses, whereas inoculation with either AM fungi or T. harzianum redirected immunity toward a salicylic acid (SA)-associated state. This shift was characterized by elevated SA accumulation, increased activity of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO), and reduced levels of JA and its derivatives. Dual inoculation reproduced these hormonal and enzymatic changes but did not further enhance them. Correlation analysis revealed that SA enrichment and PAL/PPO activities were negatively associated with pathogen abundance, whereas JA-related compounds correlated positively with disease severity. These findings suggest that beneficial fungi mitigate Fusarium wilt by reprogramming host immune responses from JA- to SA-dominated pathways, but their combined application does not produce additive benefits. This work provides new insights into the hormonal trade-offs underlying microbe-induced resistance and informs the design of microbial consortia for sustainable plant disease management.

  PublisherOA PDFDOI

• Postoperative Scoliosis After Chest Wall Tumor Resection

  2025-01-01

  book-chapter
  PublisherDOI

• Does sagittal alignment after spinal reconstruction following en bloc tumor resection impact revision rate? A preliminary long-term retrospective study

  European Spine Journal · 2025-03-15 · 2 citations

  article
  PublisherDOI

Frequent coauthors

• Ziya L. Gokaslan

  140 shared

• Adetokunbo A. Oyelese

  Brown University

  132 shared

• Jared S. Fridley

  Brown University

  130 shared

• Albert E. Telfeian

  111 shared

• Joaquin Q. Camara-Quintana

  89 shared

• Owen P. Leary

  Providence College

  86 shared

• Rahul A. Sastry

  Providence College

  72 shared

• Patricia Zadnik Sullivan

  Brown University

  56 shared

Education

• M.D.

  Medical College of Wisconsin

  2012

• B.S.

  University of Pittsburgh

  2007