Author: Scott Chamberlain
Date: 2020-04-22

# solr search

#### Scott Chamberlain

#### 2020-04-22

A general purpose R interface to Apache Solr

## Installation

Stable version from CRAN

    install.packages("solrium")

Or the development version from GitHub

    remotes::install_github("ropensci/solrium")

Load

    library("solrium")

## Setup connection

You can setup for a remote Solr instance or on your local machine.

    (conn <- SolrClient$new(host = "api.plos.org", path = "search", port = NULL))
    #> <Solr Client>
    #>   host: api.plos.org
    #>   path: search
    #>   port:
    #>   scheme: http
    #>   errors: simple
    #>   proxy:

## Rundown

`solr_search()` only returns the `docs` element of a Solr response body. If `docs` is all you need, then this function will do the job. If you need facet data only, or mlt data only, see the appropriate functions for each of those below. Another function, `solr_all()` has a similar interface in terms of parameter as `solr_search()`, but returns all parts of the response body, including, facets, mlt, groups, stats, etc. as long as you request those.

## Search docs

`solr_search()` returns only docs. A basic search:

    conn$search(params = list(q = '*:*', rows = 2, fl = 'id'))
    #> # A tibble: 2 x 1
    #>   id
    #>   <chr>
    #> 1 10.1371/journal.pone.0020843
    #> 2 10.1371/journal.pone.0022257

Search in specific fields with `:`

Search for word ecology in title and cell in the body

    conn$search(params = list(q = 'title:"ecology" AND body:"cell"', fl = 'title', rows = 5))
    #> # A tibble: 5 x 1
    #>   title
    #>   <chr>
    #> 1 The Ecology of Collective Behavior
    #> 2 Chasing Ecological Interactions
    #> 3 Ecology's Big, Hot Idea
    #> 4 Spatial Ecology of Bacteria at the Microscale in Soil
    #> 5 Biofilm Formation As a Response to Ecological Competition

Wildcards

Search for word that starts with “cell” in the title field

    conn$search(params = list(q = 'title:"cell*"', fl = 'title', rows = 5))
    #> # A tibble: 5 x 1
    #>   title
    #>   <chr>
    #> 1 Altered Development of NKT Cells, γδ T Cells, CD8 T Cells and NK Cells in a P…
    #> 2 Cancer Stem Cell-Like Side Population Cells in Clear Cell Renal Cell Carcinom…
    #> 3 Cell-Cell Contact Preserves Cell Viability via Plakoglobin
    #> 4 Transgelin-2 in B-Cells Controls T-Cell Activation by Stabilizing T Cell - B …
    #> 5 Tetherin Can Restrict Cell-Free and Cell-Cell Transmission of HIV from Primar…

Proximity search

Search for words “sports” and “alcohol” within four words of each other

    conn$search(params = list(q = 'everything:"stem cell"~7', fl = 'title', rows = 3))
    #> # A tibble: 3 x 1
    #>   title
    #>   <chr>
    #> 1 Effect of Dedifferentiation on Time to Mutation Acquisition in Stem Cell-Driv…
    #> 2 Symmetric vs. Asymmetric Stem Cell Divisions: An Adaptation against Cancer?
    #> 3 Phenotypic Evolutionary Models in Stem Cell Biology: Replacement, Quiescence,…

Range searches

Search for articles with Twitter count between 5 and 10

    conn$search(params = list(q = '*:*', fl = c('alm_twitterCount', 'id'), fq = 'alm_twitterCount:[5 TO 50]', rows = 10))
    #> # A tibble: 10 x 2
    #>    id                           alm_twitterCount
    #>    <chr>                                   <int>
    #>  1 10.1371/journal.pone.0020913               14
    #>  2 10.1371/journal.pone.0023176               12
    #>  3 10.1371/journal.pone.0023286               16
    #>  4 10.1371/journal.pone.0025390               32
    #>  5 10.1371/journal.pone.0013199               24
    #>  6 10.1371/journal.pone.0013196                5
    #>  7 10.1371/journal.pone.0009019               11
    #>  8 10.1371/journal.pone.0008993                6
    #>  9 10.1371/journal.pone.0021336               18
    #> 10 10.1371/journal.pone.0009042               18

Boosts

Assign higher boost to title matches than to body matches (compare the two calls)

    conn$search(params = list(q = 'title:"cell" abstract:"science"', fl = 'title', rows = 3))
    #> # A tibble: 3 x 1
    #>   title
    #>   <chr>
    #> 1 I Want More and Better Cells! – An Outreach Project about Stem Cells and Its …
    #> 2 Virtual Reconstruction and Three-Dimensional Printing of Blood Cells as a Too…
    #> 3 Globalization of Stem Cell Science: An Examination of Current and Past Collab…

    conn$search(params = list(q = 'title:"cell"^1.5 AND abstract:"science"', fl = 'title', rows = 3))
    #> # A tibble: 3 x 1
    #>   title
    #>   <chr>
    #> 1 I Want More and Better Cells! – An Outreach Project about Stem Cells and Its …
    #> 2 Virtual Reconstruction and Three-Dimensional Printing of Blood Cells as a Too…
    #> 3 Globalization of Stem Cell Science: An Examination of Current and Past Collab…

## Search all

`solr_all()` differs from `solr_search()` in that it allows specifying facets, mlt, groups, stats, etc, and returns all of those. It defaults to `parsetype = "list"` and `wt="json"`, whereas `solr_search()` defaults to `parsetype = "df"` and `wt="csv"`. `solr_all()` returns by default a list, whereas `solr_search()` by default returns a data.frame.

A basic search, just docs output

    conn$all(params = list(q = '*:*', rows = 2, fl = 'id'))
    #> $search
    #> # A tibble: 2 x 1
    #>   id
    #>   <chr>
    #> 1 10.1371/journal.pone.0020843
    #> 2 10.1371/journal.pone.0022257
    #>
    #> $facet
    #> list()
    #>
    #> $high
    #> # A tibble: 0 x 0
    #>
    #> $mlt
    #> $mlt$docs
    #> # A tibble: 2 x 1
    #>   id
    #>   <chr>
    #> 1 10.1371/journal.pone.0020843
    #> 2 10.1371/journal.pone.0022257
    #>
    #> $mlt$mlt
    #> list()
    #>
    #>
    #> $group
    #>   numFound start                           id
    #> 1  2349539     0 10.1371/journal.pone.0020843
    #> 2  2349539     0 10.1371/journal.pone.0022257
    #>
    #> $stats
    #> NULL

Get docs, mlt, and stats output

    conn$all(params = list(q = 'ecology', rows = 2, fl = 'id', mlt = 'true', mlt.count = 2, mlt.fl = 'abstract', stats = 'true', stats.field = 'counter_total_all'))
    #> $search
    #> # A tibble: 2 x 1
    #>   id
    #>   <chr>
    #> 1 10.1371/journal.pone.0001248
    #> 2 10.1371/journal.pone.0059813
    #>
    #> $facet
    #> list()
    #>
    #> $high
    #> # A tibble: 0 x 0
    #>
    #> $mlt
    #> $mlt$docs
    #> # A tibble: 2 x 1
    #>   id
    #>   <chr>
    #> 1 10.1371/journal.pone.0001248
    #> 2 10.1371/journal.pone.0059813
    #>
    #> $mlt$mlt
    #> $mlt$mlt$`10.1371/journal.pone.0001248`
    #> # A tibble: 2 x 3
    #>   numFound start id
    #>      <int> <int> <chr>
    #> 1   245661     0 10.1371/journal.pone.0001275
    #> 2   245661     0 10.1371/journal.pbio.1002448
    #>
    #> $mlt$mlt$`10.1371/journal.pone.0059813`
    #> # A tibble: 2 x 3
    #>   numFound start id
    #>      <int> <int> <chr>
    #> 1   237548     0 10.1371/journal.pone.0210707
    #> 2   237548     0 10.1371/journal.pone.0204749
    #>
    #>
    #>
    #> $group
    #>   numFound start                           id
    #> 1    51895     0 10.1371/journal.pone.0001248
    #> 2    51895     0 10.1371/journal.pone.0059813
    #>
    #> $stats
    #> $stats$data
    #>                   min     max count missing       sum sumOfSquares     mean
    #> counter_total_all   0 1532460 51895       0 324414287 1.533069e+13 6251.359
    #>                     stddev
    #> counter_total_all 16010.71
    #>
    #> $stats$facet
    #> NULL

## Facet

    conn$facet(params = list(q = '*:*', facet.field = 'journal', facet.query = c('cell', 'bird')))
    #> $facet_queries
    #> # A tibble: 2 x 2
    #>   term   value
    #>   <chr>  <int>
    #> 1 cell  186815
    #> 2 bird   20072
    #>
    #> $facet_fields
    #> $facet_fields$journal
    #> # A tibble: 9 x 2
    #>   term                             value
    #>   <fct>                            <fct>
    #> 1 plos one                         1946213
    #> 2 plos genetics                    72617
    #> 3 plos pathogens                   66100
    #> 4 plos neglected tropical diseases 65251
    #> 5 plos computational biology       59985
    #> 6 plos biology                     42060
    #> 7 plos medicine                    29915
    #> 8 plos clinical trials             521
    #> 9 plos medicin                     9
    #>
    #>
    #> $facet_pivot
    #> NULL
    #>
    #> $facet_dates
    #> NULL
    #>
    #> $facet_ranges
    #> NULL

## Highlight

    conn$highlight(params = list(q = 'alcohol', hl.fl = 'abstract', rows = 2))
    #> # A tibble: 2 x 2
    #>   names                 abstract
    #>   <chr>                 <chr>
    #> 1 10.1371/journal.pone… Background: Binge drinking, an increasingly common form…
    #> 2 10.1371/journal.pone… Background and Aim: Harmful <em>alcohol</em> consumptio…

## Stats

    out <- conn$stats(params = list(q = 'ecology', stats.field = c('counter_total_all', 'alm_twitterCount'), stats.facet = c('journal', 'volume')))

    out$data
    #>                   min     max count missing       sum sumOfSquares        mean
    #> counter_total_all   0 1532460 51895       0 324414287 1.533069e+13 6251.359225
    #> alm_twitterCount    0    3439 51895       0    308886 8.194604e+07    5.952134
    #>                        stddev
    #> counter_total_all 16010.71374
    #> alm_twitterCount     39.28964

    out$facet
    #> $counter_total_all
    #> $counter_total_all$volume
    #> # A tibble: 18 x 9
    #>    volume   min     max count missing      sum  sumOfSquares   mean stddev
    #>    <chr>  <dbl>   <dbl> <int>   <int>    <dbl>         <dbl>  <dbl>  <dbl>
    #>  1 11         0  300326  5264       0 26131455  498787135805  4964.  8374.
    #>  2 12         0  637916  5078       0 23045890  754959012682  4538. 11318.
    #>  3 13         0  187650  4772       0 14469852  185727513548  3032.  5453.
    #>  4 14         0  202041  4117       0  8965786  135038722582  2178.  5298.
    #>  5 15         0   56955  1558       0  3703520   44446597378  2377.  4785.
    #>  6 16         0   51981   278       0  1639028   23503754454  5896.  7069.
    #>  7 17         0   64350   145       0   957264   12461694744  6602.  6531.
    #>  8 18        10   10293    25       0    87761     452935251  3510.  2457.
    #>  9 1       2201  394613    81       0  2136280  281140741696 26374. 53009.
    #> 10 2          0  160743   483       0  7874872  316645622198 16304. 19763.
    #> 11 3          0  140263   743       0 10322036  340678112084 13892. 16306.
    #> 12 4          0  421769  1010       0 13320977  619882873519 13189. 20982.
    #> 13 5          0  261787  1539       0 17578591  518230843883 11422. 14367.
    #> 14 6          0  421511  2949       0 27083643  844617111025  9184. 14217.
    #> 15 7          0  337925  4826       0 39377491 1060307559235  8159. 12376.
    #> 16 8          0  662892  6363       0 46269702 1567973982796  7272. 13913.
    #> 17 9          0 1532460  6622       0 45978003 4777504680537  6943. 25949.
    #> 18 10         0 1245813  6042       0 35472136 3348332631936  5871. 22799.
    #>
    #> $counter_total_all$journal
    #> # A tibble: 9 x 9
    #>   journal   min     max count missing       sum  sumOfSquares   mean stddev
    #>   <chr>   <dbl>   <dbl> <int>   <int>     <dbl>         <dbl>  <dbl>  <dbl>
    #> 1 1        1443  227764  1249       0   9827787  251663612483  7869. 11819.
    #> 2 2           0  429864  1329       0  24811193 1527110853031 18669. 28304.
    #> 3 3           0  337925   355       0   7588181  509085551899 21375. 31303.
    #> 4 4        9559   19071     2       0     28630     455077522 14315   6726.
    #> 5 5           0 1245813 43312       0 236610221 9778305707321  5463. 13997.
    #> 6 6           0  181861   957       0   9440164  202232267528  9864. 10683.
    #> 7 7           0  163569  1153       0  11587785  234170621039 10050. 10108.
    #> 8 8           0  343133  2440       0  14360560  292773478918  5885.  9240.
    #> 9 9           0 1532460  1098       0  10159766 2534894355612  9253. 47170.
    #>
    #>
    #> $alm_twitterCount
    #> $alm_twitterCount$volume
    #> # A tibble: 18 x 9
    #>    volume   min   max count missing   sum sumOfSquares  mean stddev
    #>    <chr>  <dbl> <dbl> <int>   <int> <dbl>        <dbl> <dbl>  <dbl>
    #>  1 11         0  2142  5264       0 52454     11452818  9.96 45.6
    #>  2 12         0  1890  5078       0 39451     11059295  7.77 46.0
    #>  3 13         0   581  4772       0 17551      2521623  3.68 22.7
    #>  4 14         0   984  4117       0 15341      4027537  3.73 31.1
    #>  5 15         0   453  1558       0  6235       912739  4.00 23.9
    #>  6 16         0   456   278       0  2853       414803 10.3  37.3
    #>  7 17         0    44   145       0   224         5628  1.54  6.06
    #>  8 18         0     3    25       0     5           11  0.2   0.645
    #>  9 1          0    47    81       0   208         6306  2.57  8.49
    #> 10 2          0   125   483       0  1119        63677  2.32 11.3
    #> 11 3          0   504   743       0  1408       271870  1.90 19.0
    #> 12 4          0   313  1010       0  1658       155910  1.64 12.3
    #> 13 5          0   165  1539       0  2698       142098  1.75  9.45
    #> 14 6          0   972  2949       0  5733      1647077  1.94 23.6
    #> 15 7          0   864  4826       0 21873      2587889  4.53 22.7
    #> 16 8          0  2029  6363       0 40730     10857672  6.40 40.8
    #> 17 9          0  1880  6622       0 55312     17034646  8.35 50.0
    #> 18 10         0  3439  6042       0 44033     18784443  7.29 55.3
    #>
    #> $alm_twitterCount$journal
    #> # A tibble: 9 x 9
    #>   journal   min   max count missing    sum sumOfSquares  mean stddev
    #>   <chr>   <dbl> <dbl> <int>   <int>  <dbl>        <dbl> <dbl>  <dbl>
    #> 1 1           0   456  1249       0   7370       577214  5.90  20.7
    #> 2 2           0  2142  1329       0  39113     15093463 29.4  102.
    #> 3 3           0   832   355       0   5830      1219358 16.4   56.3
    #> 4 4           0     3     2       0      3            9  1.5    2.12
    #> 5 5           0  3439 43312       0 216075     61407349  4.99  37.3
    #> 6 6           0   250   957       0   8508       415112  8.89  18.8
    #> 7 7           0   230  1153       0   9273       461699  8.04  18.3
    #> 8 8           0   972  2440       0  11854      1563704  4.86  24.8
    #> 9 9           0   581  1098       0  10860      1208134  9.89  31.7

## More like this

`solr_mlt` is a function to return similar documents to the one

    out <- conn$mlt(params = list(q = 'title:"ecology" AND body:"cell"', mlt.fl = 'title', mlt.mindf = 1, mlt.mintf = 1, fl = 'counter_total_all', rows = 5))
    out$docs
    #> # A tibble: 5 x 2
    #>   id                           counter_total_all
    #>   <chr>                                    <int>
    #> 1 10.1371/journal.pbio.1001805             25190
    #> 2 10.1371/journal.pbio.1002559             13578
    #> 3 10.1371/journal.pbio.0020440             26486
    #> 4 10.1371/journal.pone.0087217             19956
    #> 5 10.1371/journal.pbio.1002191             30074

    out$mlt
    #> $`10.1371/journal.pbio.1001805`
    #> # A tibble: 5 x 4
    #>   numFound start id                           counter_total_all
    #>      <int> <int> <chr>                                    <int>
    #> 1     4900     0 10.1371/journal.pone.0098876              4302
    #> 2     4900     0 10.1371/journal.pone.0082578              3542
    #> 3     4900     0 10.1371/journal.pone.0193049              2661
    #> 4     4900     0 10.1371/journal.pone.0102159              2687
    #> 5     4900     0 10.1371/journal.pcbi.1002652              4687
    #>
    #> $`10.1371/journal.pbio.1002559`
    #> # A tibble: 5 x 4
    #>   numFound start id                           counter_total_all
    #>      <int> <int> <chr>                                    <int>
    #> 1     6461     0 10.1371/journal.pone.0155028              4235
    #> 2     6461     0 10.1371/journal.pone.0041684             29479
    #> 3     6461     0 10.1371/journal.pone.0023086             10177
    #> 4     6461     0 10.1371/journal.pone.0155989              3893
    #> 5     6461     0 10.1371/journal.pone.0223982               728
    #>
    #> $`10.1371/journal.pbio.0020440`
    #> # A tibble: 5 x 4
    #>   numFound start id                           counter_total_all
    #>      <int> <int> <chr>                                    <int>
    #> 1     1428     0 10.1371/journal.pone.0162651              3981
    #> 2     1428     0 10.1371/journal.pone.0003259              3543
    #> 3     1428     0 10.1371/journal.pone.0102679              5638
    #> 4     1428     0 10.1371/journal.pone.0068814             10143
    #> 5     1428     0 10.1371/journal.pntd.0003377              4835
    #>
    #> $`10.1371/journal.pone.0087217`
    #> # A tibble: 5 x 4
    #>   numFound start id                           counter_total_all
    #>      <int> <int> <chr>                                    <int>
    #> 1     5802     0 10.1371/journal.pone.0175497              2448
    #> 2     5802     0 10.1371/journal.pone.0204743               377
    #> 3     5802     0 10.1371/journal.pone.0159131              6664
    #> 4     5802     0 10.1371/journal.pone.0220409              1224
    #> 5     5802     0 10.1371/journal.pone.0123774              2454
    #>
    #> $`10.1371/journal.pbio.1002191`
    #> # A tibble: 5 x 4
    #>   numFound start id                           counter_total_all
    #>      <int> <int> <chr>                                    <int>
    #> 1    15002     0 10.1371/journal.pbio.1002232                 0
    #> 2    15002     0 10.1371/journal.pone.0131700              3824
    #> 3    15002     0 10.1371/journal.pone.0070448              2713
    #> 4    15002     0 10.1371/journal.pone.0191705              1971
    #> 5    15002     0 10.1371/journal.pone.0160798              4387

## Groups

`solr_groups()` is a function to return similar documents to the one

    conn$group(params = list(q = 'ecology', group.field = 'journal', group.limit = 1, fl = c('id', 'alm_twitterCount')))
    #>                         groupValue numFound start                           id
    #> 1                         plos one    43312     0 10.1371/journal.pone.0001248
    #> 2       plos computational biology     1098     0 10.1371/journal.pcbi.1003594
    #> 3                     plos biology     1329     0 10.1371/journal.pbio.0060300
    #> 4                    plos genetics     1153     0 10.1371/journal.pgen.1005860
    #> 5 plos neglected tropical diseases     2440     0 10.1371/journal.pntd.0004689
    #> 6                   plos pathogens      957     0 10.1371/journal.ppat.1005780
    #> 7                             none     1249     0 10.1371/journal.pone.0046761
    #> 8                    plos medicine      355     0 10.1371/journal.pmed.1000303
    #> 9             plos clinical trials        2     0 10.1371/journal.pctr.0020010
    #>   alm_twitterCount
    #> 1                0
    #> 2               21
    #> 3                0
    #> 4              135
    #> 5               13
    #> 6               19
    #> 7                0
    #> 8                1
    #> 9                0

## Parsing

`solr_parse()` is a general purpose parser function with extension methods for parsing outputs from functions in `solr`. `solr_parse()` is used internally within functions to do parsing after retrieving data from the server. You can optionally get back raw `json`, `xml`, or `csv` with the `raw=TRUE`, and then parse afterwards with `solr_parse()`.

For example:

    (out <- conn$highlight(params = list(q = 'alcohol', hl.fl = 'abstract', rows = 2), raw = TRUE))
    #> [1] "{\n  \"response\":{\"numFound\":32898,\"start\":0,\"maxScore\":4.737952,\"docs\":[\n      {\n        \"id\":\"10.1371/journal.pone.0218147\",\n        \"journal\":\"PLOS ONE\",\n        \"eissn\":\"1932-6203\",\n        \"publication_date\":\"2019-12-10T00:00:00Z\",\n        \"article_type\":\"Research Article\",\n        \"author_display\":[\"Victor M. Jimenez Jr.\",\n          \"Erik W. Settles\",\n          \"Bart J. Currie\",\n          \"Paul S. Keim\",\n          \"Fernando P. Monroy\"],\n        \"abstract\":[\"Background: Binge drinking, an increasingly common form of alcohol use disorder, is associated with substantial morbidity and mortality; yet, its effects on the immune system’s ability to defend against infectious agents are poorly understood. Burkholderia pseudomallei, the causative agent of melioidosis can occur in healthy humans, yet binge alcohol intoxication is increasingly being recognized as a major risk factor. Although our previous studies demonstrated that binge alcohol exposure increased B. pseudomallei near-neighbor virulence in vivo and increased paracellular diffusion and intracellular invasion, no experimental studies have examined the extent to which bacterial and alcohol dosage play a role in disease progression. In addition, the temporal effects of a single binge alcohol dose prior to infection has not been examined in vivo. Principal findings: In this study, we used B. thailandensis E264 a close genetic relative of B. pseudomallei, as useful BSL-2 model system. Eight-week-old female C57BL/6 mice were utilized in three distinct animal models to address the effects of 1) bacterial dosage, 2) alcohol dosage, and 3) the temporal effects, of a single binge alcohol episode. Alcohol was administered comparable to human binge drinking (≤ 4.4 g/kg) or PBS intraperitoneally before a non-lethal intranasal infection. Bacterial colonization of lung and spleen was increased in mice administered alcohol even after bacterial dose was decreased 10-fold. Lung and not spleen tissue were colonized even after alcohol dosage was decreased 20 times below the U.S legal limit. Temporally, a single binge alcohol episode affected lung bacterial colonization for more than 24 h after alcohol was no longer detected in the blood. Pulmonary and splenic cytokine expression (TNF-α, GM-CSF) remained suppressed, while IL-12/p40 increased in mice administered alcohol 6 or 24 h prior to infection. Increased lung and not intestinal bacterial invasion was observed in human and murine non-phagocytic epithelial cells exposed to 0.2% v/v alcohol in vitro. Conclusions: Our results indicate that the effects of a single binge alcohol episode are tissue specific. A single binge alcohol intoxication event increases bacterial colonization in mouse lung tissue even after very low BACs and decreases the dose required to colonize the lungs with less virulent B. thailandensis. Additionally, the temporal effects of binge alcohol alters lung and spleen cytokine expression for at least 24 h after alcohol is detected in the blood. Delayed recovery in lung and not spleen tissue may provide a means for B. pseudomallei and near-neighbors to successfully colonize lung tissue through increased intracellular invasion of non-phagocytic cells in patients with hazardous alcohol intake. \"],\n        \"title_display\":\"Persistence of <i>Burkholderia thailandensis</i> E264 in lung tissue after a single binge alcohol episode\",\n        \"score\":4.737952},\n      {\n        \"id\":\"10.1371/journal.pone.0138021\",\n        \"journal\":\"PLOS ONE\",\n        \"eissn\":\"1932-6203\",\n        \"publication_date\":\"2015-09-16T00:00:00Z\",\n        \"article_type\":\"Research Article\",\n        \"author_display\":[\"Pavel Grigoriev\",\n          \"Evgeny M. Andreev\"],\n        \"abstract\":[\"Background and Aim: Harmful alcohol consumption has long been recognized as being the major determinant of male premature mortality in the European countries of the former USSR. Our focus here is on Belarus and Russia, two Slavic countries which continue to suffer enormously from the burden of the harmful consumption of alcohol. However, after a long period of deterioration, mortality trends in these countries have been improving over the past decade. We aim to investigate to what extent the recent declines in adult mortality in Belarus and Russia are attributable to the anti-alcohol measures introduced in these two countries in the 2000s. Data and Methods: We rely on the detailed cause-specific mortality series for the period 1980–2013. Our analysis focuses on the male population, and considers only a limited number of causes of death which we label as being alcohol-related: accidental poisoning by alcohol, liver cirrhosis, ischemic heart diseases, stroke, transportation accidents, and other external causes. For each of these causes we computed age-standardized death rates. The life table decomposition method was used to determine the age groups and the causes of death responsible for changes in life expectancy over time. Conclusion: Our results do not lead us to conclude that the schedule of anti-alcohol measures corresponds to the schedule of mortality changes. The continuous reduction in adult male mortality seen in Belarus and Russia cannot be fully explained by the anti-alcohol policies implemented in these countries, although these policies likely contributed to the large mortality reductions observed in Belarus and Russia in 2005–2006 and in Belarus in 2012. Thus, the effects of these policies appear to have been modest. We argue that the anti-alcohol measures implemented in Belarus and Russia simply coincided with fluctuations in alcohol-related mortality which originated in the past. If these trends had not been underway already, these huge mortality effects would not have occurred. \"],\n        \"title_display\":\"The Huge Reduction in Adult Male Mortality in Belarus and Russia: Is It Attributable to Anti-Alcohol Measures?\",\n        \"score\":4.7355423}]\n  },\n  \"highlighting\":{\n    \"10.1371/journal.pone.0218147\":{\n      \"abstract\":[\"Background: Binge drinking, an increasingly common form of <em>alcohol</em> use disorder, is associated\"]},\n    \"10.1371/journal.pone.0138021\":{\n      \"abstract\":[\"Background and Aim: Harmful <em>alcohol</em> consumption has long been recognized as being the major\"]}}}\n"
    #> attr(,"class")
    #> [1] "sr_high"
    #> attr(,"wt")
    #> [1] "json"

Then parse

    solr_parse(out, 'df')
    #> # A tibble: 2 x 2
    #>   names                 abstract
    #>   <chr>                 <chr>
    #> 1 10.1371/journal.pone… Background: Binge drinking, an increasingly common form…
    #> 2 10.1371/journal.pone… Background and Aim: Harmful <em>alcohol</em> consumptio…

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